Research Progress of Carbon-Neutral Design for Buildings

Abstract

The construction industry has become one of the main drivers of the increase in carbon emissions and subsequent climate change. In this study, we focused on building carbon neutrality design and used CiteSpace V.6.2.R2 to conduct bibliometric analysis of published papers (2008–2023). After the initial screening, 280 pieces of relevant literature were obtained, including reviews, research papers, and case studies. Following further screening and excluding duplicate literature articles, 50 pieces of literature were ultimately selected as references for this paper, covering various aspects of key scientific issues, implementation approaches, and emerging research frontiers in carbon-neutral design for buildings. The research results show that significant progress has been made in energy conservation, materials, structures, systems, and operations in the research on carbon-neutral design for buildings. However, there are still issues, such as unclear implementation paths for carbon-neutral design, incomplete lifecycle assessment of carbon-neutral design, and high cost of carbon neutrality technologies in current research. Therefore, further research on the overall concept of carbon-neutral design, the progress and implementation of carbon neutrality technologies, and the integration of carbon-neutral design with sustainable development concepts are necessary. To sum up, this paper presents a thorough overview of the advancements in carbon-neutral design for buildings, examines the existing research challenges, and suggests potential avenues for future research. This paper’s findings can provide guidance for researchers, policymakers, and practitioners to promote the development and application of carbon-neutral design for buildings and to achieve sustainable development goals.

1. Introduction

Building carbon neutrality refers to the reduction of carbon emissions throughout the full lifecycle (FLC) of architecture through various technical means and design strategies, thereby achieving building carbon neutrality or carbon reduction [1]. Building carbon neutrality includes not only the carbon neutrality of the FLC of a building but also the design of building carbon neutrality. Carbon-neutral design for buildings necessitates a comprehensive assessment of the influence of carbon emissions at every phase of the building design process, thereby embracing sustainable design tactics and technologies to diminish carbon emissions across the entirety of a building’s lifecycle [2]. The implementation of building carbon neutrality requires a lifecycle approach to building design that optimizes building design, material selection, construction, and maintenance to achieve carbon neutrality throughout the building’s lifecycle. Therefore, research and practice on carbon neutrality design in buildings are of significant importance. Through regulating carbon emissions throughout a building’s complete lifecycle, carbon-neutral building design endeavors to curtail the discharge of greenhouse gases (GHGs), such as carbon dioxide, generated by buildings during the stages of design, construction, and usage. This objective aspires to yield eco-friendly and low-carbon buildings and support sustainable development. Within the framework of the building sector’s drive toward energy conservation and environmental preservation, the development of carbon-neutral design for buildings holds notable practical importance [3].

Despite significant progress in building carbon-neutral designs, there remain unresolved issues, including the technical and economic costs of such designs. While current technology and cost control methods are sophisticated, more efficient and feasible techniques and cost control measures are required to reduce carbon emission costs and increase implementation efficiency [4]. Furthermore, there are issues regarding the implementation standards and evaluation indicators for carbon-neutral building design. Current standards and indicators are not comprehensive enough to ensure the actual effect and sustainability of carbon-neutral building design [5]. Additionally, there is a need to coordinate carbon-neutral building design with urban planning and construction to ensure the sustainability of urban development [6].

This paper comprehensively reviews research progress on carbon neutrality design in buildings and performs bibliometric analysis of published papers using CiteSpace, covering bibliometric analysis methods, design methods, emerging research frontiers, hot issues in carbon neutrality design in buildings, and implementation pathways throughout its lifecycle. To begin with, the paper introduces the bibliometric analysis method, which allows for a deeper understanding of the research status and development trends of carbon neutrality design in buildings through statistical and analytical approaches to relevant literature. Then, the authors outline the design methods of building carbon neutrality from multiple perspectives, including technology, economics, and society. Based on these, the paper provides a detailed introduction to emerging research frontiers and hot issues in carbon neutrality design in buildings, such as building envelope structures, building mechanical and electrical equipment, and building energy-saving measures. This information can help identify research hotspots and frontiers in the field of carbon neutrality design in buildings, as well as enable researchers to better understand the research dynamics within the field. Finally, the authors summarize the key scientific issues of carbon neutrality design in buildings and provide prospects for its future development. The comprehensive review and analysis provided in this paper can contribute to the further advancement of research and implementation of carbon neutrality design in buildings, promoting sustainable development in the building industry.

2. Building Carbon Neutrality and Building Carbon Neutrality Design Aspects Methods for the Analysis

This paper utilized the bibliometric software CiteSpace to perform a visual analysis of literature in the field of building carbon neutrality. CiteSpace is a powerful bibliometric tool that enables large-scale bibliographic data analysis and visualization. It offers several advantages for literature research in the field of building carbon neutrality. Firstly, CiteSpace automatically generates charts such as keyword co-occurrence, author collaboration, and citation analysis, which quickly identify research hotspots and frontiers. This helps researchers to understand research dynamics within the field more effectively [7,8,9]. Secondly, CiteSpace provides visual analysis that enables researchers to understand the publication quantity, citation frequency, citation relationships, and changing trends in research topics and keywords, facilitating a better understanding of the research status and development trends in building carbon neutrality. Thirdly, CiteSpace can handle and analyze a large amount of bibliographic data and automatically generate charts and reports, significantly improving research efficiency and quality. Furthermore, through the visual analysis provided by CiteSpace, shortcomings and issues in literature research can be identified, guiding the direction and content of subsequent research. The research Technology roadmap is shown in Figure 1.

This paper utilized the Science Citation Index Expanded and the Social Sciences Citation Index databases of the Web of Science Core Collection (WoS) as the data source for the research literature. The WoS database is an electronic literature database that is widely used in bibliometric analysis, including academic materials in various fields of natural sciences and social sciences. Clarivate Analytics maintains the database, which is one of the world’s top academic journal databases, and is considered highly authoritative and credible in academia [10,11,12]. The database contains more than 25,000 scholarly journals, conference proceedings, and patent information from over 100 countries and regions worldwide, covering a broad range of fields, including natural sciences, social sciences, humanities, and engineering. Due to its high-quality academic resources and multiple analytical tools, the WoS database is widely used for academic research and evaluation, such as bibliometric analysis, citation analysis, topic analysis, and institutional ranking.

Initially, a comprehensive search of potentially relevant literature was conducted in the WoS database using keywords. The advanced search mode was used to select the core collection and precise retrieval is performed on the keywords, titles, and abstracts using combinations of terms such as “building carbon neutrality”, “carbon reduction”, “building carbon emissions”, “carbon-neutral design”, “carbon-neutral design for buildings”, and “implementation approaches for carbon neutrality in buildings”. The time period ranged from 1 January 2008 to 1 June 2023, and various source categories, such as SCI source journals, EI source journals, PKU core journals, and CSSCI, were selected. A total of 8321 articles were retrieved from the database. In order to guarantee precise data, a manual screening procedure was employed to eliminate non-academic articles and literature articles that were not pertinent to the research topic. This approach yielded a pool of 2230 relevant articles. Subsequently, the relevant articles are exported in plain text format and analyzed using CiteSpace V.6.2.R2 software. Quantitative research methods were employed to analyze the number and trend statistics of publication years, the research on the network of countries, authors, and institutional collaborations, the spatial distribution of institutions, the frequency co-occurrence of keywords, and the detection of burst words.

To a certain extent, the number of literature publications can reflect the development rate and process of research related to building carbon neutrality. Figure 2 illustrates the trend in publications on building carbon neutrality from 2003 to 2023 in this paper.

Based on the publication time distribution depicted in Figure 1, the earliest study related to building carbon neutrality dates back to 1945. The most frequently cited paper in this field is the study [13]. The authors used Middle Eastern and North African country panel data models to examine the relationship between financial development, environmental quality, trade, and economic growth. The study found that CO₂ emissions and economic growth have a bi-directional causal relationship, and economic growth and trade openness are interrelated, thus forming a bi-directional causal relationship. This paper has an average annual citation frequency of 44. The second-most frequently cited paper is the study by Zuo, Read, Pullen, and Shi, which aimed to achieve carbon neutrality in commercial building development by reducing carbon emissions [14]. The authors employed semi-structured interviews with industry professionals to identify the factors that promote or impede the attainment of carbon-neutral commercial building development. The findings indicated that the absence of a distinct definition of carbon-neutral buildings constitutes a significant obstacle in achieving this objective. The key factors identified in this study for successful carbon-neutral buildings include market demand, material selection, knowledge of facility managers, government support, and leadership. Furthermore, demonstration projects play a pivotal role in fostering a shift in culture within the construction sector. These studies provide valuable references for the development of carbon-neutral buildings. The relationship between building carbon-neutral design and the corresponding literature is depicted in Figure 3, highlighting the proportion of carbon-neutral architectural literature.

Based on the data presented in Figure 2, which depicts the proportion chart of literature on building carbon neutrality and design, several key observations can be made regarding the top-ranked journals in this field. The top six journals are as follows: Bulletin of Chinese Academy of Sciences, Urban Planning Forum, China Population, Resources and Environment, City Planning Review, and Journal of China Coal Society. The rankings offer valuable insights and information:

Focus on building carbon neutrality design: It is evident that a significant number of the top-ranked journals are dedicated to the research and development of building carbon neutrality design. This phenomenon indicates a strong academic interest and substantial publication activity in this specific area, highlighting its importance within the research community.

Integration of architectural planning and urban development: The inclusion of journals such as the Urban Planning Forum, China Population, Resources and Environment, and City Planning Review among the top six rankings emphasize the close connection between building carbon neutrality design and the broader domains of urban planning and development. This underscores the interplay and significance of urban planning and development in the context of building carbon neutrality design.

In summary, the rankings provide valuable insights into the prominence of building carbon neutrality design within the academic community. Additionally, they underscore the interconnectedness of this field with urban planning and development, shedding light on the interdisciplinary nature of research in the pursuit of sustainable and carbon-neutral architectural practices.

Attention in the field of energy is currently focused on carbon-neutral design in architecture, as indicated by the top five ranking of the Journal of China Coal Society, coal being a traditional energy source, wields considerable influence over the energy transition and carbon reduction efforts. This signifies the deep-seated interest among energy researchers and practitioners in understanding the application and impact of carbon-neutral design within the building sector. The prominence of these top-ranked journals underscores the significant academic attention devoted to carbon-neutral design in architecture, a field that is intricately connected with urban planning, urban development, and the energy sector. This emphasis holds immense value in advancing research and facilitating the practical implementation of carbon-neutral design principles in buildings. Furthermore, it serves as a catalyst for knowledge exchange and collaboration between academia and industry. The need for active involvement and contributions from experts across various fields underscores the interdisciplinary nature of carbon-neutral design for buildings.

The trend in the number of publications related to building carbon neutrality indicates a steady increase since 2011, with 223 publications in 2021 and 656 publications in 2022. The surge in research publications is primarily attributed to national policies, such as the “Green Building Evaluation Standard of the People’s Republic of China” in 2019 and the “Strategic Plan of the Central Committee of the Communist Party of China and the State Council for Accelerating the Promotion of Carbon Peaking and Carbon Neutrality” in 2021. These policies aim to improve the quality and standards of green buildings, encourage the development and utilization of green building technologies and products, and promote the transformation and upgrading of the construction industry towards green and low-carbon development. Finally, the carbon neutrality of the whole building cycle is achieved. The building sector constitutes one of the principal fields responsible for accomplishing carbon neutrality, and bolstering building energy efficiency and green constructions is imperative to realize this objective. Consequently, building carbon neutrality has become a research hotspot.

Keywords play a crucial role in academic research, as they summarize the content and highlight the main topic of the paper. In the field of carbon neutrality in the building sector, selecting appropriate keywords based on the core issues addressed in the article can effectively reflect the research focus of the field. To obtain a clearer understanding of the frequency co-occurrence of keywords, researchers often employ the pruning–slicing network method to process the data. Furthermore, clustering and threshold setting can group the map, resulting in the creation of a keyword map for English literature. By analyzing the keyword map, researchers can obtain a more comprehensive understanding of the relevant carbon neutrality issues in the building sector, providing guidance and references for further research and development in the field. Figure 4 displays the keyword map of English research on carbon neutrality in the building sector from 2003 to 2023.

According to Figure 4, research on building carbon neutrality is primarily centered on understanding “GHG” and focused on measuring “building carbon emissions”, improving the carbon-neutral design, and creating a low-carbon economic circle and industry chain. Additionally, the development and implementation of low-carbon policies are closely related to promoting the low-carbon transformation of the entire construction industry. This investigation signifies not only an unavoidable tendency in the progression of the construction sector but also exemplifies a conscientious attitude toward the worldwide climate and the environment. Furthermore, it is crucial for research on building carbon neutrality to be conducted from a global perspective in line with the requirements of the international climate change framework agreement. Figure 5 displays a comparative analysis diagram showcasing the key points pertaining to building carbon neutrality and design.

Based on the comparative analysis of keywords related to carbon-neutral design presented in Figure 5, the top five ranking keywords are as follows: carbon neutrality, peak carbon dioxide emissions, carbon reduction, climate change, and carbon emissions. The ranking order of these keywords provides valuable insights and information:

• Significance of carbon neutrality: The keyword “carbon neutrality” occupies the first rank, underscoring the prominent position of carbon-neutral design in both research and practice. This trend highlights the industry’s focused efforts to reduce carbon emissions and promote sustainable development within the building sector;
• Focus on peak carbon dioxide emissions and carbon reduction: The second- and third-ranking keywords, “peak carbon dioxide emissions” and “carbon reduction,” exemplify the emphasis placed on achieving carbon reduction targets and attaining peak carbon dioxide emissions levels through carbon-neutral design in architecture. This demonstrates the urgent need within the building industry to address climate change and mitigate greenhouse gas emissions;
• Attention to carbon emissions: The fifth-ranking keyword, “carbon emissions,” signifies the importance of considering and addressing building-related carbon emissions in the context of carbon-neutral design. By reducing carbon emissions, the building industry can take significant strides towards achieving carbon neutrality, utilizing low-carbon technologies and strategies to drive progress.

The prominence of these top five ranking keywords reflects the building industry’s deep-rooted commitment to the objectives of carbon neutrality and carbon emissions reduction, recognizing their interconnectedness with the challenges posed by climate change. These keywords provide crucial guidance for advancing research and implementing practical measures to foster carbon-neutral design in buildings, ultimately promoting sustainable development and addressing climate change targets.

International scientific cooperation is an indispensable element of scientific research, particularly collaboration among countries, which can facilitate large-scale technological innovation and breakthroughs. Figure 6 depicts the global cooperation network map, where each node corresponds to a country, and the node’s size indicates the number of publications that the country has published. The links between the nodes represent the cooperation between the countries. Regarding node size, China, the United States, and the United Kingdom are the three leading countries with the highest number of publications. Although the United States initiated its carbon neutrality research earlier, its policy lacked foresight and stability due to domestic political factors. This, in turn, hindered the research on building carbon neutrality in the United States, meaning some research results are relatively less advanced compared to China’s research. Despite commencing relatively late in the field of building carbon neutrality, China has made significant research progress, and the country attaches great importance to this area of study.

Referring to Figure 7, it is evident that universities and research institutes, primarily those specializing in environmental studies, are the primary research institutions in the field of carbon neutrality. In China, the Chinese Academy of Sciences (CAS) has the highest publication output among research institutions. The Institute of Geographic Sciences and Natural Resources Research has published more Chinese-language papers than most other institutions in China, emphasizing their active involvement in the field of carbon neutrality research. Being the country’s highest institution for natural science research, the CAS has robust research capabilities, and its research in the field of building carbon neutrality is a testament to the close relationship between this field and China’s development. The CAS’s research focuses on building energy, carbon footprints, and relevant policies, often encompassing research activities specific to particular regions of China.

Figure 8 presents the statistical data depicting the changes in the number of carbon-neutral buildings over the past five years.

Based on the statistical analysis of the quantity changes in carbon-neutral design between 2019 and 2023, as illustrated in Figure 8, several trends and proportional distributions can be discerned:

• High proportion of studies on peak carbon dioxide emissions: Among the keyword distributions related to carbon neutrality, the research on peak carbon dioxide emissions claims the highest proportion, at 10.31%. This finding highlights the significant attention within the building industry regarding the importance and urgency of attaining peak carbon dioxide emissions levels. Peak carbon dioxide emissions refer to reaching the maximum point of carbon emissions by implementing measures to reduce greenhouse gas emissions, thereby establishing a foundation for achieving carbon neutrality;
• Significant proportion of carbon reduction research: The second-ranking keyword is carbon reduction, accounting for 9.2% of the research. These data indicate ongoing efforts and research work within the building industry toward reducing carbon emissions. Carbon reduction in buildings can be achieved through energy-efficient technologies, advancements in building materials, and the implementation of design strategies, thereby mitigating the adverse impacts of climate change;
• Considerable proportion of carbon emissions research: Within the research on carbon neutrality, studies focused on carbon emissions account for 7.47% of the research. This suggests a noteworthy emphasis within the building industry on assessing and monitoring the carbon emissions of buildings. Accurate measurement and analysis of carbon emissions can facilitate the development of corresponding emission reduction measures and strategies, propelling the building industry toward carbon neutrality;
• Proportions of other keywords: Apart from peak carbon dioxide emissions, carbon reduction, and carbon emissions, there are other keywords that hold significant proportions in the research, including carbon emissions, renewable energy, and low-carbon transition. These proportions signify that the building industry is engaging in research and exploration across multiple aspects to achieve carbon neutrality and sustainable development goals.

In conclusion, the statistical analysis of the quantity changes in carbon-neutral design over the past five years reveals substantial proportions of keywords such as peak carbon dioxide emissions, carbon reduction, and carbon emissions in the research. This underscores the building industry’s attention and concerted efforts toward reducing carbon emissions, achieving carbon neutrality, and addressing climate change. Such research provides essential guidance and support for sustainable development and the realization of carbon neutrality goals within the building industry. Figure 9 shows the changes in the publications of different institutions over the past five years.

Based on the statistics presented in Figure 9, the distribution and ranking of institutions in relevant research can be observed as follows:

• Tsinghua University: Tsinghua University has emerged as the leading institution in research articles related to carbon neutrality over the past five years, with a total of 29 articles, accounting for 15.03% and securing the top position. As a renowned comprehensive university in China, Tsinghua University boasts exceptional research teams and abundant research resources, exerting substantial influence on research concerning carbon-neutral design in the building industry;
• Tongji University: Tongji University occupies the second position in the research, with a total of 19 articles, accounting for 9.84%. Tongji University holds profound disciplinary foundations and exhibits strong research capabilities in the fields of architecture and urban planning. Its research achievements have made significant contributions to the realm of carbon-neutral design in architecture;
• China Academy of Building Research: The China Academy of Building Research contributes nine articles to the relevant research, accounting for 4.66%. As an important research institution in the field of building science in China, the China Academy of Building Research is committed to promoting technological innovation and sustainable development in the building industry. Its research endeavors in carbon-neutral design have also yielded noteworthy results.

From the above data, it is evident that institutions such as Tsinghua University, Tongji University, and the China Academy of Building Research have held prominent positions in carbon-neutral design-related research over the past five years. These institutions house top-tier research teams and renowned professionals equipped with advanced research facilities and resources, which enable them to drive the advancement of carbon-neutral design in the building industry. This further underscores the widespread attention and recognition that carbon-neutral design in architecture has garnered in recent years, with related research receiving high regard from both the academic and industry communities. The research achievements of these institutions will provide crucial theoretical and practical support for the carbon-neutral transformation of the building industry, propelling its transition towards a more sustainable and low-carbon trajectory.

3. Trends in Design Methodology Research of Building Carbon Neutralization

3.1. Basic Concepts and Principles of Carbon-Neutral Design for Buildings

3.1.1. Basic Concepts of Carbon-Neutral Design for Architectures

Carbon-neutral design for buildings is a comprehensive and multifaceted approach that requires adherence to certain principles to minimize carbon emissions and achieve carbon neutrality. These principles encompass the FLC of the building, including design, construction, utilization, upkeep, and disassembly. First and foremost, it is crucial to consider the building’s FLC when designing for carbon neutrality. The core principle of carbon-neutral design for buildings is to reduce energy consumption and emissions by adopting advanced technologies and equipment and controlling emissions at the source [15]. Carbon-neutral design should also rely on the natural environment by making full use of renewable energy, optimizing the building’s layout and orientation, and improving insulation and ventilation. In addition, a comprehensive approach should be taken for the carbon-neutral design that encompasses measures related to building design, material selection, construction management, and use monitoring to minimize carbon emissions throughout the building’s lifecycle. Furthermore, carbon-neutral design should adhere to the principles of sustainable development by considering future sustainable development and integrating carbon-neutral design into the sustainable development of buildings.

Therefore, the principles of carbon-neutral design for buildings include energy conservation, advanced technology and equipment, the use of renewable energy, consideration of the building’s FLC, reliance on the natural environment, and adherence to sustainable development principles. Specific implementation methods can be pursued from these perspectives: energy-saving measures, advanced technology and equipment, utilization of renewable energy, consideration of the entire lifecycle of buildings, reliance on the natural environment, and adherence to the principles of sustainable development. Among these factors, energy-saving practices play a crucial role.

In architectural design, optimizing the appearance of buildings and employing high-efficiency thermal insulation materials and technologies can enhance the thermal insulation performance and reduce energy loss. Additionally, selecting high-efficiency energy-saving equipment and systems, such as LED lighting, intelligent building control systems, and high-efficiency heating, ventilation, and air-conditioning systems, helps minimize energy consumption. By implementing energy-saving strategies, buildings can significantly improve their energy efficiency, thereby reducing greenhouse gas emissions and contributing to carbon neutrality. These measures align with the goals of sustainable development and play a vital role in achieving carbon-neutral design in the building industry. In building design, several key factors contribute to achieving energy conservation and sustainable development. These factors include energy conservation, advanced technologies, and equipment, utilization of renewable energy, consideration of the building’s entire lifecycle, reliance on the natural environment, and adherence to the principles of sustainable development:

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Energy conservation plays a vital role in building design. By optimizing the building’s external form and employing high-performance insulation materials and techniques, thermal insulation can be improved, leading to reduced energy losses. Additionally, the selection of energy-efficient equipment and systems, such as LED lighting, smart building control systems, and efficient heating, ventilation, and air conditioning (HVAC) systems, helps minimize energy consumption;

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Integrating advanced technology and equipment is another crucial aspect of carbon-neutral design in architecture. By incorporating state-of-the-art building technology and equipment, such as intelligent energy management systems, buildings can significantly enhance their energy efficiency. Real-time monitoring, control, and optimization of energy usage through these systems enable efficient energy management. Moreover, the inclusion of energy-efficient appliances and smart meters empowers residents and users to effectively manage and control their energy consumption. These advancements in technology and equipment play a vital role in achieving carbon-neutral goals by improving energy performance and promoting sustainable practices in buildings;

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The integration and utilization of renewable energy sources hold significant importance in the pursuit of carbon-neutral design in architecture. Buildings have the capacity to effectively incorporate and harness renewable energy options, including solar photovoltaic systems, wind power, and geothermal energy. This strategic integration enables a substantial reduction in reliance on conventional non-renewable energy sources;

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In the realm of carbon-neutral design in architecture, it is crucial to consider the entire lifecycle of a building, encompassing its design, construction, use, demolition, and waste disposal stages. This holistic approach ensures that carbon-neutral principles are applied at every step, resulting in a sustainable and environmentally responsible building. During the design and construction phase, careful consideration should be given to reducing energy consumption and carbon emissions. This project can be achieved by selecting sustainable materials and employing construction methods that minimize environmental impact. Emphasizing energy-efficient designs and incorporating renewable energy systems can further enhance the building’s sustainability.

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In the pursuit of carbon-neutral design in architecture, a key aspect is relying on the natural environment to maximize energy efficiency. By leveraging natural lighting and ventilation, the dependence on artificial lighting and mechanical ventilation can be significantly reduced. In architectural design, careful consideration should be given to the orientation of the building, as well as the location and size of windows. This allows for optimal utilization of natural light, minimizing the need for artificial lighting. Through thoughtful layout and design, the integration of natural lighting can be maximized, resulting in reduced energy consumption;

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In the context of carbon-neutral design for buildings, adhering to the principle of sustainable development is crucial. This principle encompasses ecological environment protection, resource recycling, and social responsibility. It involves choosing environmentally friendly building materials, promoting construction waste classification and recycling, and reducing negative environmental impacts. Additionally, it emphasizes the importance of social sustainability by ensuring good indoor environmental quality, considering the comfort and health of building occupants, and providing a safe and comfortable living and working environment.

In terms of implementation strategies, the following specific methods can be adopted:

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Energy Efficiency: High-quality insulation materials, such as insulated windows and walls, reduce energy transfer and heat loss. Implement energy-efficient lighting systems, such as LED fixtures, to lower lighting energy consumption. Employ smart control systems to monitor and manage energy usage, optimizing energy-saving outcomes;

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Advanced Technology and Equipment: Utilize intelligent building control systems that utilize sensors and automation to control and regulate energy systems. Implement energy monitoring and management systems to track and analyze real-time energy consumption, identifying potential energy-saving opportunities. Select efficient equipment and machinery, such as high-efficiency heating, ventilation, and air conditioning (HVAC) systems, to minimize energy waste;

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Renewable Energy: Install solar photovoltaic panels to convert sunlight into electricity. Harness wind power through wind turbines for electricity generation. Consider geothermal systems that utilize stable underground temperature for air conditioning and heating. These renewable energy systems reduce reliance on traditional energy sources and decrease carbon emissions.

In conclusion, the implementation of carbon-neutral design in buildings necessitates comprehensive considerations of energy efficiency, advanced technology and equipment, utilization of renewable energy, lifecycle management, reliance on the natural environment, and sustainable development principles. The objective of carbon neutrality in buildings can be achieved by adopting specific implementation methods in these areas, leading to reduced carbon emissions, decreased energy consumption, promotion of sustainable development, and the provision of healthier and more comfortable building environments for occupants. Carbon-neutral design for buildings is an important strategy to reduce carbon emissions and promote sustainable development. Several principles must be followed in building design to achieve carbon neutrality. Firstly, the FLC of the building should be considered, from design to demolition, to minimize carbon emissions. Secondly, energy consumption and emissions should be reduced, and renewable energy sources should be used to replace traditional energy sources. Thirdly, environmentally friendly and renewable building materials should be prioritized, and carbon offsetting measures should be taken when necessary. Finally, energy management after building use is also crucial in reducing carbon emissions. Energy efficiency and energy-saving design are key aspects of carbon-neutral design for buildings. The use of efficient building insulation materials, optimized ventilation, and lighting systems, and energy-saving lighting fixtures and appliances can all reduce the energy demand of buildings and their impact on the environment. Renewable energy sources such as solar, wind, and geothermal energy should be considered to replace traditional energy sources and reduce the carbon emissions of buildings.

3.1.2. Strategies and Objectives of the Carbon Neutral Design for Buildings

Realize the Requirements of Combination Optimization of Various Design Strategies

In carbon-neutral design for buildings, achieving an optimal integration of various design strategies is paramount. This entails careful consideration of multiple factors during the design process, including energy efficiency, utilization of renewable energy, environmental adaptability, and functional requirements of the building, with the goal of finding an optimal balance among them.

To begin, it is crucial to clarify the specific requirements and objectives of each design strategy. Energy-saving strategies, for instance, focus on reducing energy consumption by optimizing the building’s exterior form, selecting suitable insulation materials, and implementing energy management systems. Strategies related to renewable energy involve integrating solar photovoltaic systems, wind power systems, or geothermal energy utilization systems. Environmental adaptability strategies necessitate considering the building’s location, climate conditions, and the utilization of natural resources to provide a comfortable indoor environment. Furthermore, a comprehensive analysis and evaluation of the interplay and potential conflicts among different design strategies are necessary. Some strategies may yield significant results in certain aspects but could adversely affect others. Therefore, when optimizing the combination of strategies, careful consideration of their weights and priorities becomes crucial to ensure the overall achievement of the optimal outcome.

The utilization of advanced computational tools and technologies becomes essential to attain the objective of optimized combinations in carbon-neutral building design. Building Information Modeling (BIM), energy simulation software, and optimization algorithms serve as valuable resources for design teams. These tools facilitate comprehensive analysis and simulation of the building’s energy performance, environmental adaptability, and overall sustainability. They contribute to informed decision-making throughout the design process by providing data-driven insights.

Furthermore, interdisciplinary collaboration plays a pivotal role in achieving the desired outcomes. Professionals from various fields, including architects, engineers, energy consultants, and environmental experts, must engage in close collaboration. Through active discussions and the pooling of their expertise and experience, these experts develop comprehensive design solutions. This collaborative approach thoroughly considers the interactions among different design strategies. By leveraging the collective knowledge of diverse disciplines, carbon-neutral building design can be optimized, resulting in the most favorable outcomes.

In conclusion, optimizing design strategies is paramount in the realm of carbon-neutral building design. The most effective design solutions can be identified by clarifying the specific requirements of each strategy, conducting thorough analysis and evaluation, harnessing advanced tools and technologies, and fostering interdisciplinary collaboration. These solutions aim to minimize carbon emissions and maximize energy efficiency in buildings. To accomplish this, the following measures can be implemented:

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Strategy integration: It is essential to ensure synergy and complementarity among different design strategies in carbon-neutral building design. For instance, when implementing energy-saving strategies, they should be seamlessly integrated with renewable energy utilization strategies to fully harness the potential of renewable energy sources and reduce dependence on conventional energy sources. Moreover, environmental adaptability strategies should be taken into account, to enable optimal building performance across diverse climatic conditions;

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Performance assessment: In the process of carbon-neutral building design, it is crucial to utilize advanced tools such as Building Information Modeling (BIM) and energy simulation software to assess the performance of different design strategies. By employing simulation and analysis techniques, the influence of various strategies on building energy consumption, indoor comfort levels, and environmental impacts can be quantitatively evaluated. This data-driven approach provides a solid scientific foundation for informed decision-making, enabling design teams to select and refine the most effective strategies that align with the project’s carbon-neutral objectives;

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It is beneficial to transform the optimization problem into a multi-objective framework to address the complex nature of combining design strategies. This approach involves establishing mathematical models and employing optimization algorithms to prioritize and weigh different design strategies based on multiple objective indicators. For instance, objectives such as energy saving and renewable energy utilization can be defined, and the optimization process can identify the optimal design solutions while considering specific constraints. By applying this approach, design teams can effectively navigate the trade-offs among various strategies and achieve synergistic outcomes that align with the project’s carbon-neutral goals;

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Interdisciplinary collaboration: It is essential to establish interdisciplinary platforms that facilitate seamless communication and cooperation to foster effective collaboration among professionals from diverse fields. Architects, engineers, energy consultants, and environmental experts should work closely together from the inception of a project to develop holistic design strategies. This collaboration should be maintained throughout the design process, with regular communication and shared decision-making to ensure that the various expertise and perspectives are integrated harmoniously;

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Continuous improvement: Achieving optimal combinations of design strategies in carbon-neutral building design is an iterative and dynamic process. Design teams should establish mechanisms for regular review and assessment of building performance, taking into account actual operational data. By analyzing the results and identifying areas for improvement, necessary adjustments, and refinements can be made to further enhance the level of carbon-neutral design.

In conclusion, the successful realization of optimized combinations of various design strategies in carbon-neutral building design necessitates a comprehensive approach encompassing strategy synergy, performance assessment, multi-objective optimization, interdisciplinary collaboration, and continuous improvement. By harmonizing these methods and strategies, the attainment of optimal outcomes in carbon-neutral building design can be achieved, thereby significantly contributing to sustainable development. Integrating these practices empowers design teams to effectively address the complex challenges associated with carbon neutrality, leading to the creation of environmentally conscious and energy-efficient buildings that align with the principles of sustainable development.

To Achieve the Goal of Emission Reduction to Energy Conservation and Then to Carbon Neutrality

In carbon-neutral building design, energy conservation and emission reduction form the core strategies for achieving carbon neutrality. By effectively reducing energy consumption and emissions, buildings can progressively attain carbon neutrality and contribute positively to addressing climate change. The following key steps and strategies are instrumental in achieving carbon neutrality objectives:

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Energy assessment and management: Conduct a comprehensive energy assessment to gain insights into the building’s energy consumption and emissions. This involves data collection, energy system monitoring, and consumption analysis. Subsequently, establish an effective energy management system to monitor usage, develop energy-saving measures, and continuously improve energy performance;

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Energy efficiency improvement: Implement measures to enhance building energy efficiency and minimize energy waste. This plan can be accomplished through approaches such as optimizing building insulation, improving facades, upgrading lighting systems to energy-efficient alternatives, and utilizing efficient equipment and appliances. Encourage occupants to adopt energy-saving behaviors to further enhance energy efficiency and rational energy usage;

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Renewable energy utilization: Actively incorporate renewable energy sources to meet building energy demands and reduce dependence on conventional fossil fuels. Integration of renewable energy technologies such as solar photovoltaic systems, wind power, and geothermal energy should be considered in building design and planning, leveraging local renewable energy resources;

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Smart controls and automation: Employ smart control systems and automation technologies to precisely regulate and manage building energy systems. These systems can dynamically adjust lighting, heating, ventilation, and air conditioning operations based on actual building usage and external environmental conditions, optimizing energy efficiency;

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Carbon offsetting and negative carbon technologies: In addition to energy conservation and emission reduction, explore carbon offsetting and negative carbon technologies to achieve carbon neutrality. Carbon offsetting involves supporting and investing in projects that reduce carbon emissions to compensate for building emissions. Negative carbon technologies, such as carbon capture and storage, aim to achieve net negative carbon emissions, surpassing carbon neutrality requirements;

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Optimization of building materials and construction: Prioritize low-carbon building materials and employ sustainable construction practices in carbon-neutral building design. Emphasize materials with low carbon footprints, including recycled materials, and those with energy-efficient lifecycles. Additionally, optimize building structures and design to minimize material usage and energy consumption;

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Lifecycle management: Consider the entire lifecycle of buildings, encompassing design, construction, operation, and demolition/recycling. Develop comprehensive strategies and measures for each phase to minimize energy consumption and carbon emissions. This involves considerations of deconstructability and recyclability during construction, energy management and maintenance during operation, and resource recovery and reuses at the end of the building’s lifecycle;

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Monitoring and evaluation: Continuously monitor and evaluate the building’s energy performance and carbon emissions after implementing the carbon-neutral design. Real-time data collection and analysis facilitate timely identification and resolution of energy waste issues, supporting continuous improvement. Regular independent energy and carbon footprint assessments ensure the ongoing achievement of carbon neutrality goals;

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Education and awareness raising: Engage in training and educational activities to enhance awareness and understanding of carbon-neutral design among building industry professionals and residents. Encourage active participation of the building industry and community in sustainable development initiatives to foster broad support and consensus.

The transition from energy conservation and emission reduction to achieving carbon neutrality can be realized by comprehensively implementing the above strategies. This reduces building energy consumption and carbon emissions and contributes positively to sustainable development and climate change mitigation. Successful implementation of carbon-neutral building design necessitates interdisciplinary collaboration, technological innovation, continuous improvement, and the cooperation of governments and relevant stakeholders.

3.2. Development Trends of Carbon-Neutral Design Methods for Buildings

3.2.1. Carbon-Neutral Evolution of Buildings in the Carbon-Neutral Perspective

Keywords such as sustainability, building energy efficiency, low-carbon buildings, and lifecycle zero-carbon buildings (carbon neutrality) are interconnected and crucial for the evolution of carbon neutrality in buildings. A close relationship exists among these keywords, forming an evolutionary process.

First and foremost, sustainable buildings are at the core of sustainable development in the construction industry. They prioritize achieving environmental, social, and economic sustainability throughout the entire lifecycle of buildings. Sustainable buildings aim to reduce resource and energy consumption, minimize carbon emissions, and provide comfortable and healthy indoor environments. Building energy efficiency plays a vital role in achieving sustainable buildings. By optimizing thermal control and adopting efficient lighting systems, equipment, and technologies, energy efficiency can be improved, leading to reduced energy consumption, carbon emissions, and operational costs.

Low-carbon buildings represent a significant direction within the realm of sustainable buildings. They focus on minimizing carbon emissions through thoughtful design, material selection, and operational practices. By utilizing low-carbon materials, implementing energy-saving measures, and incorporating renewable energy technologies, low-carbon buildings can effectively reduce their carbon footprint and mitigate their impact on climate change. Lifecycle zero-carbon buildings (carbon neutrality) represent the ultimate goal for the construction industry’s pursuit of carbon neutrality. They aim to achieve net-zero carbon emissions throughout the entire lifecycle of buildings, encompassing design, construction, operation, and demolition. Lifecycle zero-carbon buildings prioritize the reduction of both direct and indirect carbon emissions. These measures are achieved through energy efficiency improvements, utilization of renewable energy sources, and carbon offsetting measures, ultimately resulting in buildings with net-zero or even negative carbon emissions. The evolutionary process among these keywords is interconnected, with each stage building upon the previous ones in the journey toward carbon neutrality:

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Sustainable Buildings: Sustainable buildings serve as the cornerstone of the construction industry’s journey toward carbon neutrality. They prioritize the environmental, social, and economic sustainability of buildings throughout their entire lifecycle. By incorporating renewable energy sources, efficient building materials, energy-saving measures, and recycling principles, sustainable buildings can effectively reduce carbon emissions, minimize resource consumption, and provide occupants with a healthy and comfortable indoor environment;

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Building Energy Efficiency: Building energy efficiency plays a pivotal role in attaining carbon neutrality. Through the optimization of thermal control, lighting systems, equipment efficiency, and energy management practices, energy consumption can be significantly reduced, resulting in lower carbon emissions. Advanced energy-saving technologies and smart control systems further enhance building energy efficiency, fostering sustainable and low-carbon building operations;

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Low-Carbon Buildings: Low-carbon buildings aim to decrease the overall carbon footprint associated with buildings by minimizing carbon emissions from both building materials and energy consumption during operation. This entails utilizing low-carbon materials, optimizing building design, implementing energy-saving measures, and promoting the widespread adoption of renewable energy sources. Low-carbon buildings make a substantial contribution to reducing carbon emissions and serve as a critical pathway toward achieving carbon neutrality.

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Lifecycle Zero-Carbon Buildings (Carbon Neutrality): Lifecycle zero-carbon buildings, synonymous with carbon neutrality, strive to achieve net-zero carbon emissions across the entire lifespan of buildings, encompassing design, construction, operation, and demolition phases. This objective entails reducing both direct and indirect carbon emissions through measures such as energy efficiency improvements, the integration of renewable energy sources, and carbon offsetting practices. By effectively reducing the net carbon emissions of buildings to zero or even negative values, lifecycle zero-carbon buildings represent the goals and trends that will shape the future of sustainable building development.

During the progression towards carbon neutrality in the building sector, sustainable buildings, building energy efficiency, low-carbon buildings, and lifecycle zero-carbon buildings (carbon neutrality) are intricately linked, working together to drive the industry’s advancement. The following measures and methods are essential in this process:

• Comprehensive Strategies: Achieving carbon neutrality in buildings necessitates the adoption of comprehensive strategies. This entails optimizing building design, enhancing energy management, incorporating renewable energy sources, and implementing carbon offsetting measures. By thoroughly considering the carbon reduction potential in each aspect, comprehensive and feasible plans for carbon neutrality can be developed;
• Energy Efficiency: Building energy efficiency serves as a fundamental pillar in the quest for carbon neutrality. By employing efficient building insulation materials, energy-saving equipment, and intelligent control systems, energy waste can be minimized, and energy utilization efficiency can be enhanced. Regular energy assessments and monitoring should be conducted to identify and address issues related to energy waste;
• Low-Carbon Materials: The selection of low-carbon building materials is critical for reducing the carbon footprint of buildings. Priority should be given to renewable materials, recycled materials, and those with low carbon emissions, while high-carbon materials and hazardous substances should be avoided. Additionally, conducting lifecycle analyses of building materials helps assess their overall environmental impact;
• Renewable Energy: Embracing renewable energy sources is a vital approach in achieving carbon neutrality in buildings. Integration of renewable energy technologies such as solar photovoltaic systems, wind power, and geothermal energy into building energy supply is encouraged. Collaborating with local energy providers promotes developing and applying renewable energy solutions;
• Carbon Offsetting: In situations where complete elimination of carbon emissions is unfeasible, carbon offsetting can be employed to achieve carbon neutrality goals. This involves investing in carbon reduction projects, supporting sustainable development initiatives, and purchasing carbon credits to offset the remaining carbon emissions of buildings. Collaboration with carbon financial institutions and engagement with carbon markets facilitate the implementation of carbon offsetting;
• Monitoring and Evaluation: The implementation of carbon neutrality in buildings requires continuous monitoring and evaluation. Establishing effective data collection and monitoring systems helps track the energy consumption and carbon emissions of buildings. Regular carbon footprint assessments should be conducted to evaluate progress toward carbon neutrality goals and identify areas for improvement.

Through the aforementioned measures and methods, the construction industry can progressively work towards achieving the objective of carbon neutrality, thereby mitigating its impact on climate change and fostering sustainable development. However, building carbon neutrality requires interdisciplinary collaboration and diverse stakeholder engagement. Professionals from various fields, including architectural designers, engineers, energy experts, environmental scientists, and policy makers, must collaborate closely to develop carbon-neutral strategies, optimize design alternatives, and ensure coordination and cooperation during the implementation process. Furthermore, it is essential to establish a policy framework that encourages and supports carbon neutrality in buildings. This framework should include setting carbon emission limits, providing economic incentives, formulating standards, and implementing certification systems, among other measures. These efforts will facilitate the advancement of the building industry toward carbon neutrality. In summary, achieving carbon-neutral building design requires the comprehensive utilization of various strategies and methods, beginning with sustainable buildings, energy efficiency, low-carbon materials, renewable energy, and carbon emission offsets. By embracing interdisciplinary collaboration, receiving policy support, and fostering stakeholder cooperation, the construction industry can gradually work towards carbon neutrality, thereby minimizing its impact on climate change and positively contributing to sustainable development.

3.2.2. Trend of Architectural Design Method: Emission Reduction to Energy Saving and Then to Carbon Neutral

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Sustainable architectural design methods

Several methods can be considered in the context of sustainable design for achieving building carbon neutrality. Passive design is one of them, which aims to minimize the energy consumption of buildings by maximizing the use of natural climate and terrain features. This method involves the strategic placement of the building, optimizing the orientation and layout, and selecting appropriate building materials to achieve natural ventilation, lighting, and heating/cooling. Another effective method is the utilization of renewable energy technologies such as solar and wind power to reduce the reliance of buildings on non-renewable energy sources. These technologies can provide clean and sustainable energy to meet the energy demands of the building while reducing carbon emissions [16]. In addition, energy-saving technologies, including efficient insulation materials, energy-saving lighting, and intelligent control systems, are also critical components of sustainable design. These technologies can reduce energy consumption and optimize energy use to minimize carbon emissions, contributing to building carbon neutrality.

Sustainable building methods have been widely implemented, and several specific examples of their successful application exist. For instance, the Eco House in Venice, Italy, is a zero-energy office building that utilizes various technologies, such as solar, geothermal, and rainwater harvesting, to achieve nearly zero energy consumption [17]. Paseo Verde in Philadelphia, the United States, is another example of a green residential building that incorporates several energy-saving technologies, including solar panels, water-saving fixtures, and energy-efficient lighting [18]. Passive-designed residential buildings, exemplified by the R60 residential building in Freiburg, Germany, incorporate a range of energy-saving technologies, including efficient insulation, windows, solar panels, and geothermal heat pumps. Similar methods have been employed in China’s eco-city planning, such as the Shenzhen Bay Super Headquarters Base, which is an eco-city planning project that includes multiple buildings, sustainable transportation, water treatment, and energy systems. These examples demonstrate the effectiveness of sustainable building methods in achieving carbon neutrality goals while promoting sustainable development in the construction industry.

Numerous studies have been conducted on sustainable building design, and several scholars have shared their insights. For instance, Siyal, Saeed, Pahi, Solangi, and Xin developed and tested a mediation model to investigate the effect of building carbon emissions on urban areas [19]. Chen, Wawrzynski, and Lv discussed the benefits of intelligent management in architectural design [20]. According to Fenner et al., there is currently no widely recognized approach to measuring, reporting, and verifying GHG emissions from existing buildings [21]. However, as lifecycle carbon emission assessment and carbon footprint standards become more popular, differences in carbon emission calculations may arise due to variations in boundaries, scope, GHG emission units, and methodologies. Therefore, there is a growing need to develop reliable and sustainable building design methods.

Crippa et al. proposed an integrated framework that combines building information modeling (BIM) software Revit 2018 with lifecycle assessment (LCA) to simplify the process of extracting embodied carbon data [22]. This framework is of high value for the construction, engineering, and building industries, as it simplifies the process of extracting embodied carbon data and enables more accurate assessments of building sustainability.

The paper presents case studies that showcase the practical implementation of sustainable building methods and underscore their vital role in shaping the future of the construction industry. However, there are still several limitations that need to be addressed. One of the main limitations is cost issues: the implementation of sustainable building design requires high-performance building equipment, materials, and technologies, which can be costly and may impose pressure on projects with limited budgets. Another limitation is technological: sustainable design technologies are not yet widely adopted, and architects and designers may not have received relevant training and education, resulting in technological limitations. Furthermore, there are geographical limitations, as the sustainable design requires different technologies and materials in different climatic conditions, and, thus, other solutions may be needed in different regions. Finally, sustainable design is a relatively new concept, and there may be a lack of experience in its practical application, which requires a gradual accumulation of experience in practice. Overall, these limitations must be addressed to enable sustainable design to reach its full potential in the construction industry.

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Green building design method

Green building materials are an essential component of sustainable design as they aim to reduce the environmental impact of buildings.

Improving the evaluation standards for green building materials is necessary for promoting sustainability in the building industry. Green building materials are expected to be ecological, promote health, and be recyclable or high-performance. To address multiple incompatible and conflicting green building material standards, Khoshnava, Rostami, Valipour, Ismail, and Rahmat used a hybrid method to meet the sustainability encompassing the three pillars of sustainable development [23]. Their results showed that the relationship between the three independent pillars of sustainable development, green building material, and sustainability standards varied. The evaluation system and verification (the prediction of the actual effect after completion) are another most important core point: the evaluation system of green building. These evaluations and results provided valuable references for building professionals to promote sustainable building through green materials. The building industry’s global trend of “going green” has promoted various green building rating systems worldwide [24]. Lu, Chi, Bao, and Zetkulic studied the reasons behind their impact to evaluate the impact of various green building rating systems on building waste management [25]. They found that although the three green building rating systems had their own building waste management goal credits, they did not significantly promote excellent building waste management performance.

Various green building rating systems have undoubtedly played a crucial role in promoting sustainable building development. However, the performance of building waste management has not been fully promoted, possibly due to several reasons. First, rating systems tend to prioritize energy efficiency, indoor environmental quality, and water resource management, with less emphasis on waste management, leading architects and owners to de-prioritize waste management. Second, some rating systems only cover specific aspects of waste management, which may lead architects and owners to think that waste management is less important. Third, architects and owners may view waste management as an added cost and time-consuming rather than a necessary step, leading to reluctance to invest resources and effort in waste disposal. Therefore, although green building rating systems have played a vital role in promoting sustainable building development, building waste management’s importance needs to be highlighted. Architects and owners should also recognize the significance of waste management in sustainable building development.

In conclusion, the use of green building materials offers significant benefits throughout a building’s lifecycle, including reduced environmental impacts, longer service life, improved energy efficiency, and enhanced indoor comfort. Additionally, the use of green building materials can lower operational costs and increase a building’s sustainability and economic benefits. However, there are also challenges associated with green building materials, such as high production energy and water consumption, waste generation, and pollution. Furthermore, the high prices of some green building materials may increase overall building costs. Thus, when selecting green building materials, a comprehensive assessment of their environmental and economic benefits and drawbacks is crucial. Factors such as production costs, market penetration rates, and designer awareness of green materials must be considered. Therefore, a balanced approach that considers economic, environmental, and social benefits is essential in determining the optimal solution for using green building materials.

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Building energy-saving technology has evolved to zero-carbon building technology

To sum up, the objective of building energy efficiency technology is to diminish energy consumption and carbon emissions across the building’s lifecycle, from design and construction to operation and maintenance. This involves energy-saving measures in various aspects of the building, such as exterior walls, roofs, floors, doors and windows, lighting, ventilation, air conditioning, and daylighting. Common energy-saving technologies include insulation materials, thermal insulation materials, solar energy utilization, ground source heat pumps, and high-efficiency energy-saving lighting. Furthermore, the application of building energy efficiency technology requires a practical design and scheme selection based on actual conditions and user needs. Many studies have investigated building energy efficiency technology.

For instance, windows are essential building components in modern architecture that provide daylight and external views for building occupants. However, they can also contribute to high heat losses in the building envelope. Tällberg, Jelle, Loonen, Gao, and Hamdy reviewed the latest smart window products on the market and compared the energy performance of three types of smart window technologies (i.e., thermochromic, photochromic, and electrochromic) in three different locations [26]. They found that electrochromic windows are the most mature technology and can improve both visual and thermal comfort as well as the energy performance of buildings.

In the United States, building energy consumption for heating and cooling constitutes approximately 15% of the total national energy consumption. Despite numerous low-carbon footprint technologies proposed to address this challenge, most methods are limited to specific conditions and climate zones and lack flexibility. Li et al. addressed the limitations of current cooling and heating methods by introducing a dual-mode device [27]. This device features electrostatically controlled thermal contact conductance, which helps to suppress thermal contact resistance and improve surface morphology and optical properties. The result is a high cooling and heating power density of up to 71.6 W/m² and 643.4 W/m² (over 93% solar utilization). Building energy simulation analysis showed that the adoption of this dual-mode device could reduce heating and cooling energy consumption by 19.2%. This reduction is 1.7 and 2.2 times higher than those achieved with cooling-only and heating-only methods, respectively.

Hence, this type of device has significant potential for use in building energy-efficient designs to switch between different modes as needed, enabling efficient energy conversion and utilization while improving the energy efficiency of buildings. Compared to traditional building energy-saving devices, this dual-mode device can precisely control thermal contact conductivity, avoiding energy waste and reducing negative environmental impacts. Furthermore, the device can effectively regulate indoor temperature and humidity, improve indoor air quality, and create a more comfortable living environment for residents. Moreover, this device can prolong the lifespan of buildings by reducing temperature and humidity fluctuations, thus lowering the expenses of maintenance and renovation. To sum up, the adoption of the dual-mode device with electrostatically controlled thermal contact conductivity can lead to significant advantages in building energy conservation and represents a crucial avenue for future building energy-saving efforts.

The building envelope plays a critical role in ensuring that buildings provide sufficient energy and thermal comfort performance, making it a significant factor in building energy efficiency. In their recent work, Al-Yasiri and Szabó highlighted the importance of phase change materials (PCMs) in building envelope structures, specifically their use in roofs and exterior walls [28]. The authors provided a comprehensive overview of the different types of PCMs available, their general and anticipated performance, and their applications. PCMs can absorb and release heat during phase transitions, primarily from solid to liquid and vice versa, at constant temperatures. The different types of PCMs include paraffins, salts, hydrates, and metal alloys. PCMs can convert solar radiation into latent heat energy and subsequently release it to maintain comfortable indoor temperatures when the indoor temperature drops.

Consequently, PCMs significantly improve the energy efficiency performance of buildings. Although salt PCMs have relatively poor stability, they have high phase transition peak temperatures, making them suitable for some buildings in high-temperature environments. Hydrate PCMs, on the other hand, have a high phase transition heat storage density but require dehydration treatment before use. Metal alloy PCMs have a high phase transition temperatures and heat storage density but are costly and have limited applications. In summary, the use of PCMs can enhance the energy efficiency performance of buildings and decrease energy consumption to a certain extent.

In addition to the building envelope, the roof attic is a significant source of solar heat gain and tends to be much hotter than the daytime air-conditioned living space, particularly in hot regions and during summer. Thus, reducing the attic temperature can lead to a reduction in building cooling energy consumption. In their recent study, Zhao, Aili, Yin, Tan, and Yang presented a novel roof-integrated radiative air-cooling system that combines radiative sky cooling with attic ventilation [29]. The system uses metamaterials that have been recently developed for daytime radiative sky cooling and are designed to construct a 1.08 m² radiative air cooler surface to reduce attic temperature. The cooling system was found to be effective, with the air temperature measured lower than the ambient temperature under direct sunlight, depending on the airflow rate. Specifically, the air temperature decreased by 5–8 °C and 3–5 °C at night and noon, respectively. Consequently, cooling the roof attic is an efficient building energy-saving approach, especially during the summer heat season, as partial shading of the direct sunlight on the roof attic can effectively lower indoor temperature by reducing indoor solar radiation and heat gain. Lower indoor temperatures result in reduced frequency and duration of air-conditioning system usage, leading to reduced energy consumption and energy-saving effects. Furthermore, cooling the roof attic can enhance the living environment by reducing indoor heat, improving indoor air quality, and increasing indoor comfort. Additionally, it can slow down the aging and damage of building materials, thereby extending the building’s service life.

In conclusion, energy-saving technologies have progressed through continuous development and innovation. However, there are limitations and challenges that need to be addressed. The effectiveness of building energy-saving technologies in addressing climate change and energy scarcity is not yet significant enough, and a more comprehensive and systematic strategy and measures are required. The application and promotion of building energy-saving technologies are also constrained by various factors such as economics, policies, and culture. Therefore, further strengthening policy support and market promotion is necessary. Moreover, building energy-saving technologies face technical and cost issues that require constant exploration, innovation, and cost reduction. In addition, the sustainability of building energy-saving technologies should be considered to avoid causing new environmental problems and resource waste. Thus, there is still great potential for the development of building energy-saving technologies, and concerted efforts and cooperation from all parties are necessary to strengthen technological innovation, policy support, and market promotion. These efforts will help promote the application and development of building energy-saving technologies and achieve sustainable development goals.

3.3. Carbon Footprint and Carbon Neutral Design Methods for Buildings

3.3.1. Assessment Method of Building Carbon Footprint

The carbon footprint assessment method is an essential tool for evaluating a building’s carbon emissions during its entire lifecycle, including construction, use, and demolition. This method enables architects and developers to develop emission reduction plans by identifying opportunities to reduce carbon emissions. A number of scholars have contributed to the development of carbon footprint assessment methodologies. For instance, Yang, Hu, Wu, and Zhao proposed a BIM-based lifecycle assessment method to promote low-carbon design in the context of China’s smart building, engineering, and construction transformation [30]. Through a case study of residential buildings’ carbon footprint calculation, the authors found that the building’s carbon footprint accounted for 69% of total GHG emissions during the operational procedure, while the production of architecture materials accounted for 24%. Thus, a detailed assessment of a building’s environmental performance throughout its lifecycle using BIM-based building lifecycle assessment modeling can guide the development of low-carbon building designs.

Efforts to quantify and reduce carbon footprints are not limited to conventional buildings, as the healthcare sector, transportation, and energy industries are also making strides in this area. The international agreement on reducing Carbon footprint has been put into practice. For example, on 9 December 2022, the European Council and the European Parliament reached a temporary political agreement on the proposal to strengthen the sustainability rules for batteries and waste batteries. The agreement stipulates that electric vehicle batteries must provide a carbon footprint statement before they can be put on the market or put into use. In academic research, Tennison et al. proposed a hybrid model to quantify GHG emissions over the past two years, which supplements widely used top-down economic models with more precise bottom-up data where available [31]. All organizations play an essential role in global GHG emissions, including higher education institutions that are a significant part of the global education system, crossing international borders, social-political systems, and economic systems. Robinson, Tewkesbury, Kemp, and Williams introduced a universal, standardized method for calculating the carbon footprint of higher education to address climate issues through carbon reduction policies, both inside and outside of buildings [32]. This method may also be applicable to all organizations regardless of industry or region, with the exclusion of purchased products and services typically included in Scope 3 footprints. The mandated reporting of carbon emissions can help regulate carbon emissions from buildings in this sector and aid in achieving carbon reduction goals.

The construction industry has a significant environmental impact due to the extensive use of raw materials, consumption of fossil energy, and subsequent GHG emissions. To mitigate this, the use of natural and sustainable materials has gained attention, and hemp products and byproducts (fibers and shives) have shown promise due to their good hygrothermal and acoustic performance. Scrucca et al. conducted an LCA of French hemp crop cultivation to evaluate its energy and environmental impact [33]. The assessment revealed both positive and negative contributions related to different lifecycle stages. Despite the challenges, the biological carbon captured and stored during hemp growth resulted in a lower total carbon footprint assessment. Hemp material is particularly suitable for use as insulation and coating materials, especially in the form of fiber mats. This is an important sustainable feature as the material is biodegradable and retrievable. The widespread adoption of hemp products in construction could potentially contribute to reducing the construction industry’s environmental impact.

In recent years, the energy consumption of public buildings has risen significantly, and the assessment of carbon footprints has become crucial in quantifying building energy consumption. Trovato, Nocera, and Giuffrida conducted an economic and environmental evaluation of a standard energy retrofit project for public buildings in the Mediterranean region [34]. They integrated LCA into traditional economic and financial evaluation models. The study found that sustainable retrofitting strategies, such as double-glazed windows with wooden frames, organic external wall insulation systems, and green roofs, can significantly reduce the building’s heating and cooling energy demand and CO₂ emissions by 58.5% and 33.4%, respectively. The use of sustainable materials, in comparison to standard materials, also led to a 54.1% reduction in the building’s carbon footprint index after retrofitting, resulting in an additional 18% in social, environmental, and financial benefits.

Gardezi and Shafiq shared their experience in the housing sector in Malaysia, where they developed innovative predictive models for operational carbon footprints during the planning and design phase, in addition to LCA methods [35]. The authors employed multiple regression analysis to examine the impact of various factors on the selected case study. They also created a 3D parameter model of the case study in a virtual environment using BIM. The findings indicated that meeting statistical standards and performing tests resulted in an accurate predictive model with a percentage error of ±6 between predicted and observed values. This investigation contributes to the pre-assessment of carbon dioxide and enables rapid, sustainable decision-making and safe green social development using the early stage of lifecycle research.

The selection of carbon footprint assessment methods should be based on several factors, such as the evaluation object, data availability, and accuracy requirements. Different methods are applicable in various contexts, including individual, corporate, or national-level assessments. Furthermore, the choice of assessment method should consider its operability and repeatability. Carbon footprint assessment methods serve as tools to guide sustainable design and decision-making. By assessing the carbon footprints of products, services, activities, and organizations, carbon emission sources can be identified and quantified, which can help formulate measures and strategies to reduce carbon emissions and mitigate climate impact. For instance, companies can reduce their emissions by identifying opportunities to reduce their carbon footprint, developing emission reduction plans, and implementing corresponding measures. However, carbon footprint research also has limitations. Firstly, carbon footprint assessment can only evaluate the environmental impact from the perspective of GHG emissions and cannot comprehensively assess other environmental factors such as water resources and land use. Secondly, the quality and availability of data, particularly in global assessments, are limited by the reliability of data. Additionally, the methods and assumptions used in carbon footprint assessments may contain errors and uncertainties. Finally, carbon footprint assessments need to consider the impact of the FLC to ensure the comprehensiveness and accuracy of the assessment results. Therefore, when conducting carbon footprint assessments, it is necessary to recognize the limitations of the evaluation results and attempt to maximize the quality and availability of data to obtain more accurate and comprehensive evaluation results.

3.3.2. Carbon Footprint and Building Carbon-Neutral Design Methods

Table 1. Development trend of carbon-neutral design methods for buildings.

Author + Year	Type	Method	Contribution
Tennison et al. (2021) [31]	Overview	Proposing a Hybrid Model for Quantifying the Carbon Footprint of Greenhouse Gases	Top-down economic model
Robinson et al. (2018) [32]	Method	Higher Education Carbon Footprint Standard Approach	Various types of contributions to GHG emissions
Yang et al. (2018) [30]	Method	LCA based on building information model	Evaluating the prospective lifecycle environmental performance of buildings
Xiao, Wang, Ding, & Akbarnezhad (2018) [36]	Method	Carbon footprint of two identical twin towers investigated	Natural aggregate concrete
Crippa et al. (2018) [22]	Method	BIM	Sustainable design methods
Ramadan et al. (2022) [37]	Method	How to use the advantages of titanium dioxide to improve the performance of concrete	Kaolin as a blended cement or geopolymer
Alsulaili, Al-Matrouk, Al-Baghli, & Al-Enezi (2020) [38]	Survey verification	Use of eco-friendly materials in the house and conduct a questionnaire survey	Environmentally friendly paint instead of ordinary paint
Ghedini et al. (2020) [39]	Method	Formulating environmentally friendly, inexpensive, and readily available materials for green building applications	High surface area TiO2–SiO2 is promising as a new generation of green building materials
Tällberg et al. (2019) [26]	Method	Comparing the energy-saving potential of adaptive and controllable bright windows	Electrochromic technology is the most mature
Li et al. (2020) [27]	Method	dual-mode devices with electrostatically controlled thermal contact conductivity	Save energy for heating and cooling
Trovato et al. (2020) [34]	Method	Evaluation of Energy Retrofits for Public Building Standards in the Mediterranean Region	Sustainable materials can effectively reduce the carbon footprint index

provides a concise overview of the key contributions to the evolving trend of carbon-neutral design methods for buildings.

Upon reviewing Table 1 and the preceding text, it is clear that the field of building carbon neutrality design has undergone significant developments, including advancements in carbon footprint assessment methods, green building materials, building energy-saving technologies, renewable energy utilization technologies, and sustainable design methods.

International standards and regulations and GHG protocols have been established to assist in the assessment and management of building carbon footprints [40]. The use of green building materials, including renewable, recycled, and low-carbon materials, is a critical aspect of building carbon neutrality design. With the continuous development of technology, new energy-saving equipment and technologies, such as LED lighting, intelligent control systems, and high-efficiency thermal insulation materials, are increasingly becoming the norm. Incorporating renewable energy utilization technologies, such as solar energy, wind energy, and geothermal heat pumps, is also essential for building carbon neutrality design. Sustainable design methods encompass integrating the concept of sustainable development throughout the building design, construction, and operation process to minimize building carbon emissions.

As the demand for carbon neutrality in the building industry continues to grow, building carbon neutrality design methods will continue to evolve and improve. Future development will focus on exploring new carbon neutrality technologies and methods, such as the use of carbon capture and storage technologies. The integration of carbon neutrality design with urban planning will be strengthened to achieve carbon neutrality interaction between buildings and cities. Additionally, promoting carbon marketization to incentivize the practice and development of building carbon neutrality will be crucial. There is still much work to be done in this field.

4. Emerging Research Frontiers and Hot Issues in Carbon-Neutral Design for Buildings

The design bias in carbon-neutral building design encompasses the tendency to focus on reducing carbon emissions during the design process in order to achieve carbon neutrality goals. This bias encompasses multiple aspects of building design, including material selection, energy utilization optimization, and the design and integration of building systems.

Regarding material selection, the design bias emphasizes the prioritization of low-carbon and renewable materials to minimize carbon emissions and resource consumption. For instance, utilizing efficient insulation materials and energy-saving windows can lower building energy consumption and reduce dependence on traditional energy sources. In terms of energy utilization, the design bias calls for optimizing energy supply and utilization methods in buildings to decrease energy consumption and carbon emissions. This involves the adoption of renewable energy technologies such as solar power and wind energy to replace conventional fossil fuel sources. Additionally, the incorporation of building energy management systems and smart control technologies is crucial within the design bias. Furthermore, the design bias underscores the importance of considering and integrating building systems to optimize energy efficiency and reduce carbon emissions. Through system integration and optimization, not only can building energy utilization efficiency be enhanced, but energy waste and environmental impact can also be minimized.

The significance of the design bias in carbon-neutral building design should not be underestimated. It guides architects and relevant stakeholders to prioritize carbon reduction and sustainability throughout the design process, propelling the building industry toward carbon neutrality. Simultaneously, the design bias reminds us of the need to balance various design objectives and requirements, ensuring that the functionality, comfort, and aesthetics of buildings align with carbon neutrality goals. Consequently, in both research and practical applications of carbon-neutral building design, thoroughly exploring and resolving design bias issues is imperative to drive the building industry towards greater progress in carbon reduction and sustainable development.

Building carbon neutrality is a major research focus in the field of architecture, with ongoing expansion and deepening of related research areas. The evolution of research hotspots in this field can be revealed through methods such as timeline spectra and keyword cluster analysis [41]. Timeline spectra can display the appearance and evolution of different clustering focuses, thereby helping researchers understand the development of various research fields. Keyword cluster analysis can reflect scholars’ attention to certain keywords during specific periods, facilitating the identification of research hotspots at that time. CiteSpace V.6.2.R2 software can generate these maps, as shown in Figure 9. The research frontiers and trends in building carbon neutrality can be comprehensively understood by analyzing the clustering keywords in the figure.

An examination of the evolution of research hotspots in the field of building carbon neutrality, depicted in Figure 10, reveals that the research focus has undergone multiple changes. Initially, the research was primarily focused on the development and application of carbon neutrality technologies, but it later shifted to areas such as carbon footprint assessment and management methods, sustainable design methods, building energy-saving technologies, and green building materials. Moreover, the timeline chart indicates that scholars have shown varying degrees of interest in different research topics during different time periods. For instance, the combination of building carbon neutrality and renewable energy has gradually become one of the research hotspots in recent years. In summary, exploring the evolution of research hotspots in the field of building carbon neutrality can provide a better understanding of the research direction and future development trends of this field. Based on the current research status, this paper analyzes the emerging research frontiers and hotspots in building carbon neutrality design from four aspects: building carbon circular economy, low-carbon building design, energy self-sufficient buildings, and building carbon capture and utilization (CCU) technologies.

4.1. Building the Carbon Circular Economy

The carbon circular economy is a sustainable economic model with the dual objectives of economic growth and environmental protection. It aims to maximize the recovery, reuse, and regeneration of carbon resources while minimizing carbon emissions [42]. The principles that underpin the carbon circular economy involve reducing carbon emissions and increasing carbon recovery and utilization rates. These principles include three aspects: first, reducing carbon emissions through the adoption of clean energy, promotion of energy-saving technologies, and improvement of production processes; second, increasing carbon recovery and utilization rates by recycling, reusing, and regenerating carbon resources; and third, promoting carbon trading to encourage enterprises and individuals to trade carbon emission rights through the carbon trading market, thus achieving the goal of emission reduction.

Implementing the building carbon circular economy necessitates adopting a range of strategies and crucial technologies, such as (1) Reusing building materials, which constitutes a significant component of the building carbon circular economy. By recycling building waste and producing industrialized recycled building materials, building materials can be regenerated and reused, thereby reducing resource waste and carbon emissions. Building waste can be repurposed via the classification and circulation of materials. Recycled building materials, such as recycled concrete, steel bars, and glass, can reduce energy consumption and carbon emissions during the production process of building materials; (2) The utilization of building energy-saving technology represents another vital technology for realizing the building carbon circular economy. Deploying building insulation, ventilation, and lighting technologies can lower building energy consumption and carbon emissions from energy use. Furthermore, building energy-saving technology encompasses water-saving technology, water-saving irrigation systems, etc.; (3) The use of building carbon neutralization technology constitutes another key technology for building the carbon circular economy. Carbon neutralization technology encompasses carbon capture, carbon sequestration, and carbon emission reduction technology. In the building carbon circular economy, building carbon neutralization technology can reduce the carbon emissions of buildings by employing carbon-neutral materials in building design and construction or by realizing carbon absorption and sequestration through plant cultivation, among other methods.

The sustainable operation and management of buildings is an additional crucial approach toward achieving a building carbon circular economy. building sustainability practices include water and energy conservation, environmental protection, and health management. By implementing green management systems, intelligent operation and management, and other techniques, the sustainable operation of buildings can be achieved, thereby reducing resource consumption and carbon emissions. However, while the building carbon circular economy has extensive potential, it also has its share of limitations and challenges, such as insufficient awareness and motivation among stakeholders in the construction industry and the lack of standardization and consistency in carbon footprint assessment methods. The subsequent section will present specific research cases to illustrate these challenges.

One example of specific research is the study conducted by Gholami and Røstvik, which evaluated the economic benefits of using photovoltaic building design systems as a structural material for building envelopes [43]. The study found that the Building Integrated Photovoltaic (BIPV) system can recover all facade investments using a zero discount rate, even in the north. However, there are rarely additional benefits after the investment compared to traditional building envelope structural materials. The social and environmental benefits of European BIPV systems are most significant on the south facade. In addition, for all building envelope research directions in Europe (except for the north facade with a discount rate of 5), the quantification of only the social and environmental benefits of the BIPV system can almost pay back all investment costs. Therefore, the BIPV system can not only reimburse all investment costs but also become a source of income for the building if used as a structural material for the entire building envelope.

Hong et al. conducted a comprehensive study on the optimization of building energy retrofitting, considering energy, environmental, and economic factors [44]. They proposed an energy-environment-economy coordinated optimization method that integrates a lifecycle cost assessment of building energy retrofitting options to achieve the best energy performance for buildings. The proposed method incorporates energy savings, environmental impact, and economic benefits of different energy-saving options, and evaluates the overall benefits of building energy retrofitting from a macro perspective, using lifecycle cost as the evaluation index. Although this approach reduces the lifecycle cost of buildings while ensuring energy efficiency, it requires comprehensive data support and cost evaluation for implementation and does not fully consider the policy and regulatory impact on building energy retrofitting. Furthermore, factors such as building service life and maintenance that may affect lifecycle costs are not taken into account, and further enhancements and optimizations are necessary.

Norouzi, Chàfer, Cabeza, Jiménez, and Boer conducted a systematic and comprehensive review of the research hotspots in the circular economy within the construction industry over the past decade [45]. The study covered areas such as sustainable building design, recycled building materials, construction waste management, and building energy efficiency and provided insights into future development directions for the circular economy in the construction industry. The authors identified key themes and trends in the existing literature and suggested areas for further research, including the recycling of building materials, LCA, and building energy conservation. While the study provides valuable guidance and references for stakeholders in the construction industry, it is limited by its focus on existing research and the lack of original research results. Furthermore, given the construction industry’s complexity and diversity, significant technical and management challenges need to be addressed to fully implement a circular economy.

The method of optimizing energy efficiency model of architectural design is the key to building carbon neutral design, which hope to strengthen this part. In their study, Hong, Kim, and Lee developed a multi-objective optimization model to assess the impacts of building design and occupants’ behavior on energy, economic, and environmental performance [46]. The goal of the model was to create the best possible building designs and occupant behavior plans by taking into account how each would affect the facility’s energy use, financial costs, and carbon emissions. The authors also analyzed thermal comfort and energy consumption using EnergyPlus and quantified the economic and environmental values through lifecycle cost analysis and LCA. The primary contribution of this study was the development of a multi-objective optimization model for building design and occupants’ behavior, which can be an effective decision-making tool for building designers and planners to create more energy-efficient, environmentally friendly, and economically sustainable buildings. However, the model’s limitations may include being restricted to certain geographic locations and climate conditions. Therefore, building design and occupants’ behavior strategies under specific conditions may require further research and improvement.

Ma, Hao, Zhang, Guo, and Di Sarno studied the issue of carbon footprint in the building industry and proposed a comprehensive circular economy assessment model [47]. The main achievement of this research is the establishment of a system dynamics-LCA causal loop model, which can assess the carbon emissions resulting from building renovation, construction, and demolition waste and provide corresponding policy recommendations to reduce carbon emissions based on the assessment results. The model considers different sources of carbon emissions, such as energy consumption, material use, and transportation, as well as their interactions. However, this piece of literature also has some limitations, such as a narrow focus solely on carbon emissions and a lack of evaluation of other environmental and social factors. Additionally, the model still requires further support and validation from practical data and cases to enhance its reliability and validity.

The main research contributions of the above construction carbon circular economy concepts are summarized in

Table 2. Development status of building carbon circular economy methods.

Author + Year	Type	Method	Contribution
Gholami & Røstvik (2020) [43]	Method	Evaluating the economic benefits of photovoltaic building designs as a building envelope material	Reimburses all investment costs and becomes a source of construction income
Hong et al. (2021) [44]	Method	A comprehensive study on the optimization problem of building energy-saving retrofit	Building energy-saving renovation based on coordinated energy-environment-economic optimization
Norouzi et al. (2021) [45]	Review	Systematically sorting out the research progress of circular economy in the field of construction	Guiding the construction industry toward a circular economy
Hong, Kim, & Lee (2019) [46]	Method	Quantifying economic and environmental value through lifecycle cost analysis and valuation analysis	Quantifying the economic and environmental value of buildings
Ma et al. (2022) [47]	Method	A comprehensive, holistic model for assessing carbon emissions from BR C&D waste	Visual waste management

.

The implementation of a carbon circular economy in the building industry presents various technological challenges. For instance, the recycling and reuse technology of building materials are not yet mature, and the quality of recycled materials is uncertain. Additionally, the assessment and management of carbon footprint in building design, construction, and operation demand specialized technical support and significant investment costs, which are difficult to overcome and hinder the popularization of a carbon circular economy in buildings. Furthermore, the lack of standardization and uniformity in carbon footprint assessment methods is a significant bottleneck for the development of a carbon circular economy in buildings. Currently, carbon footprint assessment standards and methods are not fully standardized, resulting in various regions and organizations using different carbon footprint assessment methods. This diversity makes it challenging to compare and share carbon footprint data across different regions and industries, hindering the promotion and implementation of a carbon circular economy in buildings. The absence of a unified measurement standard and data support makes achieving the full potential of a carbon circular economy in buildings challenging.

Extending the lifespan of buildings is a crucial strategy for achieving carbon-neutral design. By prolonging a building’s lifespan, its inherent carbon emissions can be distributed over a longer period, thus reducing its overall environmental impact. Implementing strategies to extend building lifespans involves several key aspects:

(1)

Building design and construction: Consideration should be given to the durability and maintainability of the structure during the design and construction phases. This includes selecting high-quality building materials and employing advanced construction techniques to ensure the stability and reliability of the building’s structure and systems. Sensible design of use spaces, taking into account functional changes and adaptability, is also important to meet the requirements of different stages;

(2)

Maintenance and upkeep: Establish regular maintenance and upkeep plans, including periodic inspections, cleaning, repairs, and replacement of damaged or aging components and equipment. Regular maintenance helps extend the lifespan of building elements and equipment, prevents minor issues from escalating into major problems, and enhances the overall performance and functionality of the building;

(3)

Renovation and retrofitting: Periodically evaluate the building’s functional and technological requirements and undertake necessary updates and retrofits. This may involve adopting energy-efficient alternative equipment and technologies to improve the building’s energy efficiency and performance. Sustainable building updates and retrofits should be pursued using renewable and recyclable materials to minimize resource consumption and environmental impact;

(4)

Education and awareness-raising: Enhance the awareness and knowledge levels of building users and maintenance personnel through education and training. This action empowers them to use and maintain building facilities correctly. Users should be educated on proper building usage and maintenance practices to minimize unnecessary wear and damage. Maintenance personnel should receive training in techniques for maintaining building systems and equipment, ensuring proper operation and an extended lifespan;

(5)

Management and monitoring: Establish a building management system to regularly monitor and assess the performance and condition of the building’s lifespan. By collecting data and employing advanced building management techniques, potential issues can be identified promptly, and appropriate measures can be taken to address them. This ensures long-term sustainable operation and an extended lifespan for the building.

By comprehensively implementing the aforementioned strategies, the lifespan of buildings can be maximized, thereby reducing resource consumption and carbon emissions. This benefits environmental protection and sustainable development and yields economic advantages by reducing maintenance and renovation costs and enhancing the value and competitiveness of buildings. Therefore, extending the lifespan of buildings is a crucial aspect of carbon-neutral design, and establishing long-term planning and management mechanisms is essential for the successful implementation of lifespan extension strategies. The following measures provide further detail:

• Building material selection: Choose high-quality and durable building materials, considering their long-term performance and lifespan. Prioritize the use of sustainable materials, including renewable and recyclable materials, to minimize environmental impact and extend the lifespan of building components;
• Preventive maintenance: Establish regular inspection and maintenance plans, including periodic checks of the building’s structure, equipment, and systems to identify and address potential issues. Regular cleaning and upkeep of building elements such as roofs, walls, and floors prevent damage and corrosion, thus prolonging their lifespan;
• Technical monitoring and data analysis: Utilize advanced technology monitoring systems to continuously monitor the performance and operation of the building in real-time. Potential issues can be identified by collecting and analyzing data, and the building’s operations can be optimized, thereby extending its lifespan and improving energy efficiency;
• Renovation and retrofitting: Periodically assess the building’s functional requirements and technological needs and undertake necessary updates and retrofits. Incorporate advanced energy-efficient technologies and equipment to enhance the building’s energy efficiency and performance. Simultaneously, integrate required system upgrades and improvements as part of the building’s renovation plan to accommodate evolving needs and technological advancements;
• Education and awareness-raising: Enhance the awareness and knowledge levels of building users, maintenance personnel, and management staff through training and education programs. Educate users on the proper use of building facilities and equipment, providing appropriate maintenance guidance. Train maintenance personnel and management staff on best practices and maintenance techniques for buildings, enabling them to effectively manage and maintain the building and implement measures to extend its lifespan.

By considering the comprehensive implementation of these measures and integrating them into the entire process of building design, construction, maintenance, and management, the lifespan of buildings can be maximized. This will help reduce resource consumption and environmental impact, promote the realization of carbon-neutral design, and contribute to sustainable development. Moreover, extending the lifespan of buildings can yield economic benefits by reducing maintenance and renovation costs and enhancing the value and sustainability of buildings.

The lack of awareness and driving force among stakeholders in the construction industry is a significant factor that constrains the development of the building carbon circular economy. The construction industry involves a multitude of stakeholders, including designers, constructors, developers, owners, and government regulatory agencies. Achieving the building carbon circular economy requires these stakeholders’ joint efforts and support. However, some stakeholders lack sufficient understanding of the concept of carbon footprint and the benefits of a carbon circular economy, leading to a lack of enthusiasm and motivation to promote its development. This challenge highlights the need to strengthen technical research and innovation, improve the construction of standardized and unified carbon footprint assessment methods, and enhance the awareness and driving force of stakeholders in the construction industry. Promoting these factors will be key to the widespread application of building a carbon circular economy.

4.2. Low-Carbon Architectural Design

Low-carbon building design is a comprehensive approach that aims to reduce GHG emissions and energy consumption across the entire lifecycle of a building, from design and construction to use and demolition. This is achieved through selecting appropriate building materials, adopting energy-efficient technologies and measures, and optimizing building design solutions to minimize the negative impact of buildings on the environment and resources [48]. The principles and objectives of low-carbon building design focus on reducing buildings’ carbon footprint throughout their lifecycle, thereby promoting environmental protection and sustainable development. Some common principles and objectives of low-carbon building design are the following:

(1)

Minimizing energy demand: This can be achieved by using high-efficiency insulation materials and building techniques, as well as designing lighting and ventilation systems to reduce energy consumption;

(2)

Utilizing renewable energy: Buildings can use renewable energy sources such as solar and wind power to meet their energy demands and reduce dependence on traditional energy sources;

(3)

Using low-carbon building materials: Buildings can be constructed with renewable and low-carbon materials to reduce carbon emissions.

These principles can also be used to minimize water demand by using low-flow devices and collecting rainwater. Sustainable design strategies can be incorporated by considering ecological and environmental factors in building design and using green landscapes, rainwater harvesting, and sustainable discharge strategies. Building operations can also be optimized through energy-saving measures, monitoring, and management of building energy consumption. By adopting these low-carbon building design principles and objectives, it is possible to reduce the carbon footprint of buildings while increasing their sustainability and environmental friendliness. To achieve the goals of low-carbon building design, various key technologies and strategies are required, including carbon footprint assessment and management methods, building energy-saving techniques, passive design, renewable energy utilization technologies, and the application of green building materials. In this regard, there are some specific low-carbon building design applications and evaluation methods that can be illustrated.

One such example is provided by Echenagucia, Moroseos, and Meek, who offered practical guidance and a priority framework for building designers, owners, and policymakers to establish coordinated optimization of lifecycle carbon performance for facade components and assemblies under various climate environments and energy carbon intensities [49]. The ambit of this study, enshrining the empirical investigations of building envelope structures, unfurled on a grandiose scale, delving into the precincts of six prominent cities across the United States of America. The crux of the study pivoted upon the building performance simulations and embodied carbon calculations, whereby a comprehensive assessment of the total carbon emissions was facilitated, with particular emphasis on commercial office and residential space types. The optimization of total carbon emissions, in tandem with the standard code reference models and open-source lifecycle data, attained a lofty exaltation, positioning the study at the vanguard of empirical investigations within the sphere of building envelope structures. However, it must be noted that the relationship between embodied carbon and operational carbon is not a panacea, being highly localized in nature, and subject to significant variations within the precincts of diverse design variables. For instance, excessive investment in envelope embodied carbon may exceed 10 kgCO₂e/m in low-carbon intensity energy grids.

Chen, Dang, and Du conducted a study on the production of low-carbon and lightweight strain-hardening cement composites using low-grade calcined clay, a waste material from construction and excavation projects [50]. The researchers investigated the effect of calcined clay content (20%, 40%, and 60% by weight) on the hydration, microstructure, strength, ductility, shrinkage, and embodied carbon of the cement composites. This study effectively addressed the issues of high self-weight, low tensile strength, poor toughness, and low tensile strain capacity of conventional concrete.

In a separate study, Liu developed a radial basis function neural network algorithm for a low-carbon circular economy in forest areas [51]. The researchers designed a coupled development evaluation model and explored the operational mode, and updated formula of the algorithm. The study also optimized the RBF neural network using a particle swarm optimization algorithm. To overcome the issues of premature convergence and poor search capability in the particle swarm optimization algorithm, the authors proposed an improved algorithm that nonlinearly adjusts inertia weight and introduces an average extreme value factor to enhance the search accuracy and capability. The study developed a multi-dimensional, multi-constraint, and multi-model industrial ecological structure optimization prediction model, set up economic and social development scenarios, and optimized the prediction of low-carbon industrial ecological structures in forest areas. Based on the simulation analysis of the prediction results, the authors proposed directions for adjusting the industrial ecological design and paths for constructing the industrial ecosystem.

The LCA, conducted by Luo, Cang, Zhang, Yang, and Liu, was founded on a process-based approach aimed at ascertaining the carbon emissions emanating from a vast array of materials intricately woven within the realm of residential buildings, office buildings, and commercial buildings, totaling 129, 41, and 21, respectively [52]. Through an ingenious stroke of genius, the authors put forward a simplified model, with the ostensible aim of calibrating and measuring the embodied carbon emissions, right from the inception of the building design phase. The salient findings of the study, swathed in a plethora of data, and predicated on the exhaustive analysis of an exhaustive array of building materials, effectively demystified the primary sources of carbon emissions, squarely pegged at 10 building materials comprising steel, reinforced concrete, wall materials, mortar, copper core cable, architectural ceramics, polyvinyl chloride pipes, insulation materials, doors and windows, and water-based paint. The authors advanced the notion of reducing the quantity of these materials during the building design phase, all while embracing environmentally friendly alternatives, thereby ameliorating the ravaging impact of carbon emissions on the delicate ecosystem.

Waibel, Evins, and Carmeliet introduced a collaborative simulation framework for optimizing building geometry and multi-energy systems using energy hub methods [53]. They formulated a bi-objective optimization problem to minimize operational costs and carbon emissions and provided decision variables for building geometry and energy system technology selection and scale. The method was applied to four office buildings in Zurich, Switzerland. The results suggested that environmental objectives should be determined based on the building’s location. Rural areas potentially have stricter objectives than densely populated urban areas to reflect their respective marginal costs of achieving objectives. Integrating building elements, such as geometry, energy system design, and local solar potential, through the coupling of various simulators can optimize the design workflow for low-carbon buildings.

Panteli, Kylili, and Fokaides discussed research trends in building design and optimization before construction, analyzed issues related to the environmental assessment of building design using BIM and LCA tools, and considered monitoring and coordination using BIM during construction and health and safety topics at the construction site [54]. When examining the post-construction application of BIM, the authors considered the latest research on using the Internet of Things technology for intelligent building operations and the application areas of renovation projects. They proposed interoperability issues related to data sharing between BIM-related applications based on the latest developments in standardized processes.

Table 3. Development status of low-carbon building design methods.

Author + Year	Type	Method	Contribution
Echenagucia et al. (2023) [49]	Case verification	Parameter optimization of commercial office and residential space types	Localization of the relationship between embodied and operational carbon
Chen et al. (2022) [50]	Method	Low-grade calcined clay as cement material	Improving the defects of ordinary concrete
Liu (2021) [51]	Method	Radial neural network algorithm for low carbon circular economy	Optimizing the prediction of ecological structure of low-carbon industry in forest area
Luo et al. (2019) [52]	Method	Calculation of embodied carbon emissions during the building design phase	Detecting building material types with high emissions
Waibel et al. (2019) [53]	Method	Co-simulation framework	Optimizing building geometry and multi-energy systems
Panteli et al. (2020) [54]	Review	A review of research trends in the field of architectural design and optimization	BIM in intelligent buildings

summarizes the main research contributions of low-carbon building design described in the aforementioned texts.

Low-carbon building design has gained significant attention and widespread adoption globally. The significance of carbon reduction as a crucial objective in building design is increasingly being acknowledged by architects, designers, developers, and policymakers. The adoption of low-carbon building design practices involves various technologies and methods, such as energy efficiency and clean energy, low-carbon materials and processes, and renewable energy.

However, low-carbon building design still faces limitations and challenges. Firstly, it requires additional investment and costs, including higher construction costs and longer payback periods, which may discourage some developers and property owners. Secondly, it requires greater technical expertise and knowledge, necessitating architects and designers to possess more skills and abilities. Additionally, there is a lack of uniformity and recognition in certification systems for low-carbon building design across different countries and regions, posing difficulties for multinational companies engaged in low-carbon building design.

In conclusion, low-carbon building design is an inevitable trend in future building development, but it requires further refinement and development in practice. Policymakers, industry organizations, enterprises, and academic institutions need to collaborate to improve the standards and certification systems for low-carbon building design, reduce the costs and investment risks of low-carbon building design, and enhance the technical and professional capabilities of low-carbon building design. This will promote the dissemination and development of low-carbon buildings, and enable us to achieve a more sustainable future.

4.3. Energy Self-Sufficient Buildings

4.3.1. Building Applications of Renewable Energy

The application of renewable energy in building energy conservation is an inevitable and essential development trend. Accelerating the adoption of renewable energy sources such as solar energy, biomass energy, and wind energy to directly or indirectly fulfill buildings’ energy needs for hot water, heating, air conditioning, electricity, and lighting not only substitutes limited traditional energy sources but also enhances the quality of life and residential comfort for urban residents. Moreover, it significantly reduces the consumption of conventional primary energy sources, serving as a vital pathway to achieve carbon neutrality and peak emissions in buildings.

There are various approaches to incorporating renewable energy in buildings. Firstly, the utilization of solar energy is of paramount importance. Solar photovoltaic systems can convert solar energy into electricity to fulfill the building’s power requirements. These systems can be installed on the roof, facade, or other suitable locations of the building to capture solar energy and generate electricity. Additionally, solar thermal utilization systems can harness solar energy for hot water, heating, and air conditioning purposes in buildings. Solar water heaters and collectors can absorb heat from solar energy to heat water sources or provide air conditioning cooling.

Secondly, biomass energy can be effectively applied in buildings. Biomass energy, including biomass fuels and biogas, can be utilized for heating and power generation purposes. Biomass energy can be converted into heat or electricity for the building’s energy needs through equipment such as biomass boilers and biogas generators. The use of biomass energy not only reduces reliance on traditional energy sources but also helps decrease greenhouse gas emissions, contributing to the building’s carbon neutrality objectives.

Furthermore, wind energy holds significant potential as a renewable energy source. Buildings can harness wind power through wind turbines to generate electricity for their power requirements. Wind turbines can be installed on the roof, facade, or suitable locations near the building to capture wind energy and generate electricity. Wind power generation not only provides clean electricity for buildings but also reduces energy costs and carbon emissions.

In conclusion, the integration of renewable energy in buildings presents a significant opportunity to decrease resource consumption and carbon emissions. By harnessing solar, biomass, and wind energy, buildings can enhance their energy efficiency, promote sustainability, and contribute to a greener and more sustainable future.

In addition to solar energy, biomass energy, and wind energy, there are various other renewable energy sources that can be effectively utilized in buildings. One such source is geothermal energy, which harnesses underground heat for heating and cooling purposes. Geothermal heat pump systems or ground water circulation systems can collect and utilize geothermal energy, utilizing the stable underground temperature to meet the building’s energy needs. This approach conserves traditional energy resources and reduces the building’s carbon emissions.

Furthermore, hydropower is an important renewable energy source. Hydropower can generate electricity and provide sustainable power supply for buildings situated in suitable geographical conditions by harnessing the kinetic energy of flowing water. Buildings can employ hydropower technologies such as water turbines or tidal power devices to convert water energy into electricity, thereby reducing reliance on conventional energy sources.

When incorporating renewable energy in buildings, it is essential to consider the building’s energy requirements and the availability of renewable energy resources. This necessitates a comprehensive analysis of the building’s energy consumption and the identification of suitable renewable energy technologies and equipment. Additionally, factors such as the design, installation, and ongoing maintenance of renewable energy systems must be taken into account to ensure their efficient operation and reliability.

Moreover, policy and economic factors play a significant role in driving the adoption of renewable energy in buildings. Governments can incentivize the use of renewable energy in the construction industry by implementing policies and regulations that encourage its integration and offering financial and tax benefits. Concurrently, ongoing efforts to reduce the costs of renewable energy technologies and enhance their economic competitiveness will further accelerate their application in buildings.

In conclusion, the application of renewable energy in buildings is a critical pathway toward achieving carbon neutrality goals and fostering sustainable development. By effectively harnessing solar energy, biomass energy, wind energy, geothermal energy, and other renewable sources, it becomes possible to minimize traditional energy consumption and carbon emissions in buildings while simultaneously improving energy efficiency and sustainability. Strong policy support and continuous technological advancements are vital for driving the widespread adoption of renewable energy in the building sector, ultimately leading to carbon neutrality in the industry.

4.3.2. Building Design Principles of Energy Self-Sufficiency

Energy self-sufficient buildings, also known as “zero-energy buildings” or “net-zero energy buildings,” refer to buildings that achieve a net energy consumption of zero or close to zero on an annual basis under normal operating conditions through the effective use of renewable energy and energy-efficient technologies. The design principles of these buildings mainly include maximizing the utilization of renewable energy, adopting energy-efficient technologies, utilizing flexible energy management systems, and recycling building materials to minimize waste and environmental pollution.

In order to maximize the utilization of renewable energy, energy self-sufficient buildings require devices such as photovoltaic cells and wind turbines, which convert solar and wind energy into electricity for internal power and lighting. Energy-efficient technologies, including high-efficiency insulation materials, ventilation systems, and geothermal heat pumps, are critical to minimizing energy consumption.

Real-time monitoring of internal energy consumption and optimization of energy usage can be achieved through flexible energy management systems that control lighting, air conditioning, heating, and other devices in the building. Lastly, utilizing recyclable building materials is essential to reducing waste and environmental pollution. Despite the wide recognition of the concept and principles of energy self-sufficient buildings, the practical implementation of such buildings still faces certain limitations. These limitations include high technology costs, restrictions on the building’s structure and purpose, the complexity of energy management systems, and incompatibility with existing energy systems. Therefore, further research and promotion are necessary to realize the practical application of energy self-sufficient buildings.

Attaining energy self-sufficient buildings requires the integration of several key technologies, namely renewable energy technologies, building energy management and control systems, and energy storage and conversion technologies. In the following sections, we will discuss some specific examples and evaluation methods of energy self-sufficient buildings to illustrate these key technologies.

Rosati et al.conducted an assessment of the climate-independent scaling law for integrating battery storage in residential buildings [55]. The study evaluated the environmental and economic impacts of different capacity lithium-ion batteries in existing residential buildings located in different climates. The authors developed a model to simulate all building elements and energy consumption using a case building consisting of 13 apartments equipped with a reversible heat pump, photovoltaic system, and lithium-ion batteries. Measured data were used to validate the results.

The study reveals that sustainable investments in battery storage can be achieved in all climates by optimizing the lithium-ion battery size based on variations in renewable energy self-consumption. Techno-economically, lithium-ion batteries are best suited for daily storage as they efficiently bridge the gap between energy demand and production each day. However, investing in lithium-ion batteries is not a sustainable solution for seasonal storage, even considering foreseeable cost reductions. Optimized building-level battery storage alone cannot completely address the time mismatch between energy production and consumption, and hence, the adoption of other technologies, such as electric mobility, should also be considered to consume all the energy produced by the photovoltaic system.

In another study, Villasmil, Troxler, Hendry, Schuetz, and Worlitschek used numerical investigations to examine the impact of various collector control strategies on the performance of a seasonal thermal energy storage solar heating system in low-energy residential buildings [56]. Their objective was to achieve a solar fraction of 100% annually while minimizing the storage volume required. Three controllers were assessed, and the results revealed that the performance characteristics of each controller were closely related to the thermal stratification in the storage and the controller’s ability to maintain stratification throughout the year.

Amato, Bilardo, Fabrizio, Serra, and Spertino devised a stupefying test facility at the Politecnico di Torino in Italy to investigate an all-electric, nearly zero-energy building design that could achieve energy self-sufficiency [57]. The facility incorporated an air-source heat pump, photovoltaic generators, and dynamic simulation models to assess energy performance. The research aimed to enhance energy self-sufficiency by scrutinizing the incorporation of lithium-ion batteries into the energy supply system and optimizing storage size. The facility was partitioned into three units with distinct power systems to estimate the benefits of local energy sharing. The simulation outcomes were befuddling, indicating that the facility achieved anticipated energy performance commensurate with European nearly zero-energy buildings. Local use of photovoltaic energy could be increased through battery use and local energy sharing, resulting in greater self-reliance from the external power grid.

Trancossi, Cannistraro, and Pascoa conducted a study on an innovative thermal pump and electric coupling that combined solar energy and thermodynamic energy and evaluated its implementation in energy-efficient residential container houses [58]. The proposed design offers personalized settings based on specific building needs, followed by an assessment of the building and air conditioning systems based on the first and second laws of thermodynamics. Results showed that environmental adaptability could be achieved through thermal recovery from parabolic troughs and photovoltaic modules during the winter, and a complete analysis and sizing of the building and thermal pump were provided, demonstrating the advantages of the proposed system. The main contributions of the research on self-sufficient buildings are summarized in

Table 4. Development status of energy self-sufficient buildings.

Author + Year	Type	Method	Contribution
Rosati et al. (2022) [55]	Method	Case building modeling	Lithium-ion battery storage optimization for buildings
de Rubeis, Falasca, Curci, Paoletti, and Ambrosini (2020) [59]	Method	Heating performance of energy self-sufficient buildings	Climate change highlights the dramatic reduction in heating energy demand.
Villasmil et al. (2021) [56]	Method	Solar heating system performance	Controller-specific performance related to thermal storage
Amato et al. (2021) [57]	Case test	Energy assessment of photovoltaic test facilities	Facility energy performance meets zero energy building requirements
Trancossi et al. (2020) [58]	Method	Innovative heat pumps for solar and solar coupling	Solar gain of transparent elements clarified

.

The concept of energy self-sufficient buildings is a highly promising architectural design concept that can reduce reliance on traditional energy sources and minimize negative environmental impact. With the development of renewable energy technologies such as solar and wind power, more and more energy self-sufficient buildings have been constructed and achieved success.

However, energy self-sufficient buildings still face some limitations. The design and construction costs of energy self-sufficient buildings may be higher than those of traditional buildings, limiting their popularity and promotion. Furthermore, the design and operation of energy self-sufficient buildings require a high level of technical and professional knowledge, as well as interdisciplinary skills from different fields. The varying climates, terrains, and resource conditions in different regions require customized and optimized designs based on environmental factors, presenting challenges for promoting energy self-sufficient buildings.

To promote the application of energy self-sufficient buildings, further research and development are needed, including the development of more intelligent and sustainable energy technologies, exploration of new design and construction methods, and the establishment of comprehensive policies and standards to encourage and support the development and promotion of energy self-sufficient buildings. Strengthening education and training to cultivate more professional and technical personnel can promote the development and application of energy self-sufficient building technologies.

4.4. Building CCU Technology

The field of building CCU involves a range of technologies that capture, recover, and utilize carbon dioxide emissions from buildings. These technologies can be broadly categorized as passive or active [60]. Passive technologies rely on the structure and materials of buildings to facilitate CCU, such as through natural processes involving plants, soil, and minerals that convert carbon dioxide into organic matter. While passive technologies are relatively simple and low-cost, they have limited efficiency and require a long period of time to achieve significant CCU. On the other hand, active technologies use devices and technical means such as artificial climate control, chemical reactions, and storage technologies to achieve CCU. These approaches have the potential to achieve higher levels of efficiency and faster results but are generally more expensive to implement.

The technology of CCU in buildings involves capturing, recovering, and utilizing carbon dioxide emissions within buildings through various technical means. These technologies can be categorized as passive or active. Passive technologies utilize the structure and materials of buildings to capture and utilize carbon, such as natural processes such as plants, soil, and minerals. This technology is relatively simple and low-cost, but its efficiency is limited and requires a longer natural process. On the other hand, active technologies capture and utilize carbon dioxide through devices and technical means, such as artificial climate control, chemical reactions, and storage technologies. This technology can achieve CCU in a shorter period with higher efficiency but at a relatively higher cost.

Additionally, CCU technology in buildings can be categorized based on the utilization method of carbon, which includes storage, conversion, and utilization. Storage technology involves storing captured carbon dioxide underground or elsewhere to prevent it from entering the atmosphere. Conversion technology involves converting carbon dioxide into other useful substances, such as fuel or chemicals. Utilization technology involves using carbon dioxide for other applications, such as plant growth or building material production.

However, the implementation of CCU technology in buildings is still in the research and development phase, and there are technical and economic limitations and challenges in its application, such as technical costs, energy consumption, and social acceptance. Therefore, further exploration and research on these technologies are needed to achieve more sustainable carbon reduction and utilization in buildings.

The implementation and key technologies of CCU in buildings include carbon capture technology and carbon utilization technology, such as carbonization and carbon fixation. The analysis of the application cases and evaluation methods of CCU technology in buildings shows that carbon capture, utilization, and storage (CCUS) is a technological approach for managing anthropogenic carbon dioxide emissions into the atmosphere. Hills, Tripathi, and Carey discussed the basis for mineralization of geological and industrial waste, with a focus on creating valuable products [61]. The study assessed mineralization of building aggregates and indicated that CCUS technology could manage large amounts of carbon dioxide in such building materials.

The increasing demand for concrete due to global urbanization and economic development has led to a rise in the demand for new buildings and infrastructure. In this context, Skocek, Zajac, and Ben Haha conducted experiments to demonstrate the feasibility and reactivity of carbonated regenerated fines derived from concrete that can be utilized in laboratory and industrial materials under different mineralization conditions [62]. The study revealed that complete carbonation of the fines could sequester all CO₂ initially released during the clinker production process through limestone calcination within a short time. After complete carbonation, the fines developed gel-like characteristics similar to volcanic ash, regardless of the testing conditions. The use of carbonated fines can result in over 30% reduction in CO₂ emissions compared to utilizing limestone as a substitute for clinker.

He, Wang, Mahoutian, and Shao conducted a study to explore the potential of utilizing captured cement kiln flue gas to accelerate carbon dioxide sequestration and hydration in various cement-based building products [63]. The authors proposed an innovative process that involved the carbonation of flue gas, injection, and release of five cycles within seven hours. The study showed that the degree of carbonation of flue gas was lower than that of pure gas, but the strength gain was similar. The reaction products were typical calcium silicate hydrate carbonates, which were carbonate-modified hydrates. The crystal sizes of the carbonate minerals produced through flue gas carbonation were much smaller than those produced through pure gas carbonation. However, they contributed similarly to strength gain. The successful capture and utilization of cement kiln flue gas can establish a network connecting cement plants and concrete plants for emission reduction through utilization.

Kuittinen, Zernicke, Slabik, and Hafner published a review article on potential carbon storage technologies to achieve carbon neutrality, focusing on the construction industry [64]. The authors classified existing carbon storage technologies into 13 methods and evaluated their net carbon storage impact and maturity, providing ranking recommendations based on applicability, impact, and maturity. The study found that the potential for systematically accumulating atmospheric carbon in the built environment is not fully utilized.

Table 5. Development status of building CCU technology.

Author + Year	Type	Method	Contribution
Hills et al. (2020) [61]	Method	Evaluation of mineralized construction aggregate	Carbon capture contributes to building carbon emissions.
Skocek et al. (2020) [62]	Method	Complete carbonation case study of fine powder	Sequestration and reactivity of carbonated regenerated fines
He et al. (2020) [63]	Method	Common cement-based building products for flue gas carbonization	Building a network connecting cement plants and concrete plants
Meys, Kätelhön, Bardow (2019) [65]	Method	CO2 LCA-base rubber	Impact of global warming is reduced by up to 34%.
Kuittinen et al. (2023) [64]	Review	Carbon storage technologies are reviewed	Atmospheric carbon potential is underutilized.

summarizes the main research contributions of CCU technologies in the construction industry.

The current state of research and development in CCU technologies in the building sector is being actively pursued worldwide. Numerous laboratories and research institutions have made significant strides in experimentation and testing, yielding promising results. For example, various novel carbon capture materials and technologies, such as metal-organic frameworks, porous organic polymers, nanomaterials, and biomass materials, have been developed. These materials and technologies have demonstrated effective CO₂ capture and fixation from the air, converting it into valuable substances. Some large-scale building projects have implemented carbon capture materials to decrease building carbon emissions and utilize captured CO₂ for producing new building materials or other industrial purposes.

However, these technologies’ practical application and promotion are still met with challenges and limitations, such as high costs, technological immaturity, regional restrictions, and potential adverse environmental impacts. In conclusion, building CCU technologies is a crucial direction for developing low-carbon buildings. Still, their implementation and promotion necessitate further research and practical testing to address technological and economic barriers and ensure minimal environmental impact.

5. Ways to Achieve Carbon Neutrality in the Whole Building Cycle

5.1. Concept and Importance of Building Lifecycle Carbon Neutrality

Achieving carbon neutrality throughout a building’s lifecycle has become increasingly important as part of efforts to address climate change. This comprehensive strategy aims to offset all GHG emissions associated with a building, including emissions from materials production, construction, use, maintenance, and demolition, by implementing measures that reduce and offset these emissions, such as energy conservation and the use of renewable energy sources [66]. The goal is to achieve zero or negative carbon emissions throughout a building’s lifecycle. The concept of building lifecycle carbon neutrality has been proposed and promoted as a means of achieving sustainable development in the construction industry, reducing negative environmental impacts, and creating healthier and more comfortable indoor environments [67].

The study of FLC carbon neutrality of buildings is crucial, due to the significant contribution of the building industry to global energy consumption and GHG emissions. Currently, industry accounts for about 40% of the total global carbon emissions, and, thus, reducing carbon emissions in the building industry is vital in achieving global carbon neutrality goals. Moreover, FLC carbon neutrality can increase the value of buildings, reduce operating costs, improve the social image and brand influence of companies, and promote sustainable development in the building industry. Emphasizing the importance of FLC carbon neutrality has several benefits. Firstly, it can help achieve global carbon reduction goals by significantly reducing emissions from the building industry. Secondly, it can enhance the sustainability of buildings by promoting environmental protection and energy conservation and the adoption of environmentally friendly, energy-efficient building methods and materials. Finally, it can promote the development of the building industry by encouraging coordination and collaboration among all stages of the building industry chain, thus facilitating industry upgrade and development.

5.2. Ways to Realize Carbon Neutrality in the Full Cycle of Buildings

5.2.1. The Design of Architectural Carbon Neutral Design Technology Is a Mathematical Model Architecture (The Artificial Neural Network Learns the Mapping Relationship between Input and Output from the Data, etc.) System

The design of carbon-neutral building technologies is a complex and interdisciplinary process that necessitates the integration of knowledge and techniques from various fields. Mathematical modeling systems play a crucial role in this process by offering a systematic and quantitative approach to analyze and assess the carbon-neutral potential of buildings, aiding in decision-making. Among the components of the mathematical modeling system, artificial neural networks hold significant importance. Artificial neural networks are mathematical models that emulate the structure and functionality of the neural system in the human brain. By inputting a dataset, artificial neural networks can learn intricate relationships between data and adjust the network’s weights and biases through training, facilitating accurate mappings between inputs and outputs. In the context of carbon-neutral building design technologies, artificial neural networks find application in building energy consumption models, carbon emission prediction models, and other areas, assisting designers in evaluating the carbon-neutral effects of different design solutions.

Additionally, the mathematical modeling system can incorporate other models and algorithms, such as optimization algorithms and data analysis techniques. Optimization algorithms enable the search and iteration for the optimal combination of design parameters to achieve the building’s carbon-neutral objectives. Data analysis techniques extract valuable information and patterns from extensive datasets, enabling designers to comprehend the energy consumption characteristics and carbon emission trends of buildings, thus making informed decisions based on analytical results. The mathematical modeling system for designing carbon-neutral building technologies must consider factors from various perspectives, including building structure, material properties, and energy supply methods. The design of carbon-neutral building technologies necessitates a comprehensive consideration of these factors, finding the most favorable trade-off solutions. Through the utilization of the mathematical modeling system, designers can simulate and evaluate multiple scenarios, consequently formulating specific carbon-neutral strategies and design solutions.

For instance, Płoszaj-Mazurek, Ryńska, and Grochulska-Salak conducted a study focused on regenerative design and parameterized modeling, resulting in the development of a simulation-based design guide [68]. Through the generation of training and test sets of building designs, the study calculated the total carbon footprint. Subsequently, a machine learning model was trained using the pre-generated dataset, enabling the prediction of optimal building features for rapid estimation of the total carbon footprint. The results of this multi-criteria analysis demonstrated the relationship between building parameters and the potential integration of carbon footprint estimation in the initial design phase, thereby facilitating building optimization.

Likewise, Patterson et al. presented four best practices aimed at reducing energy consumption and carbon dioxide emissions during machine learning training [69]. The study highlighted that widespread adoption of these best practices within the machine learning field could lead to a significant decrease in total carbon emissions from training by 2030. Furthermore, Karaman, Karaman, Show, Karimi-Maleh, and Zare investigated the impact of pH, initial dye concentration, temperature, and contact time on biosorption capacity [70]. They employed scanning electron microscopy and N₂ adsorption/desorption isotherms to analyze the biosorption kinetics, equilibrium, and thermodynamics. The experimental data were utilized to optimize artificial neural network models, employing various network architectures. The biosorption kinetic model revealed that the biosorption capacity followed pseudo-second-order and saturation-type kinetic models.

In conclusion, the design of carbon-neutral building technologies relies on a sophisticated mathematical modeling system. This system, incorporating techniques such as artificial neural networks, enables a systematic and quantitative analysis of the carbon-neutral potential of buildings, facilitating the development of carbon-neutral strategies and solutions. Ongoing improvements and applications of the mathematical modeling system contribute to the advancement of the building industry toward carbon neutrality and sustainable development. Future research and practice should explore expanding the application areas of the mathematical modeling system, investigating novel algorithms and technologies to enhance the accuracy and efficiency of carbon-neutral building design.

On the one hand, the mathematical modeling system can be refined and optimized to cater to various types and scales of building projects. Residential, commercial, and public buildings exhibit distinct energy consumption characteristics and carbon emission patterns, necessitating tailored mathematical modeling systems. Moreover, different scales of building projects, such as individual buildings, building clusters, and urban planning, require carbon-neutral design considerations at different levels. Thus, the mathematical modeling system should possess flexibility and scalability to address these diverse requirements.

On the other hand, integration of the mathematical modeling system with technologies and data from other fields can offer comprehensive solutions for carbon-neutral building design. For instance, the incorporation of Building Information Modeling (BIM) technology allows for the integrated management of building design, construction, and operation processes, optimizing carbon-neutral design strategies. Furthermore, coupling the mathematical modeling system with big data analytics technology enables the utilization of vast amounts of building energy consumption and environmental data to unveil hidden patterns and rules, delivering more accurate guidance and predictions for carbon-neutral design.

Moreover, the development of the mathematical modeling system should be accompanied by the establishment of policies and standards to facilitate the practical application and promotion of carbon-neutral building design technologies. Appropriate policies and standards provide legal and normative support for carbon-neutral design in the building industry, guiding the adoption of advanced mathematical modeling systems and carbon-neutral technologies. Furthermore, collaboration between the building industry and academia, through research cooperation and the sharing of practical case studies, can drive the application and advancement of the mathematical modeling system.

In summary, the design of carbon-neutral building technologies is a complex process reliant on a mathematical modeling system. With continuous technological advancements and widespread adoption, the mathematical modeling system will assume an increasingly pivotal role in carbon-neutral design within the building industry. Through ongoing research and innovation, the mathematical modeling system can be further refined to enhance the effectiveness and feasibility of carbon-neutral building design, thereby facilitating sustainable development and the transition to a low-carbon building industry.

5.2.2. Multi-Index System for Evaluation of Building Carbon Neutral Design Technology (Construction of Carbon Neutral Evaluation of Gray Correlation Analysis Algorithm)

The evaluation of carbon-neutral building design technologies aims to accurately assess and compare the performance of different design schemes in terms of carbon-neutral goals. To achieve a comprehensive evaluation, a multi-criteria system must be established, considering various aspects of building energy efficiency, carbon emissions, and sustainability.

Constructing a multi-criteria system involves selecting appropriate evaluation indicators that objectively reflect the carbon-neutral characteristics and performance of buildings. Energy efficiency is an important indicator for evaluating carbon-neutral building design, considering the energy consumption and utilization efficiency of buildings to assess their energy performance and carbon emission levels. Additionally, factors such as material utilization efficiency and water resource utilization efficiency can be considered to comprehensively evaluate the sustainability of buildings. The gray relational analysis is a commonly used evaluation method in multi-criteria systems. This algorithm determines the importance and contribution of different indicators to carbon-neutral building design by assessing the degree of correlation between the indicators. Through data processing and analysis of different indicators, the correlation between each indicator can be determined, enabling the assignment of weights and ranking of evaluation results. This allows designers to optimize design schemes and enhance the carbon-neutral performance of buildings based on the evaluation results.

In response to government policies on climate change and increasing awareness of sustainable development, manufacturing organizations face growing pressure to reduce their current emission levels. To address these challenges, the industry needs to employ tools such as lifecycle assessment to measure and analyze environmental waste. In a study conducted by Kaswan and Rathi, advanced decision-making tools were utilized to identify, investigate, and prioritize the barriers to implementing lifecycle assessments in the Indian manufacturing industry [71]. Gray relational analysis and the best-worst method were employed for further validation. The research revealed that key obstacles to implementing lifecycle assessment include a lack of support from top management, inadequate environmental management education and training for employees, and insufficient collaborative efforts among supply chain partners to collect relevant data.

Gui et al. studied a low-carbon-oriented product lifecycle design method, which involved modularizing products into functional units to determine their carbon footprints [72]. The carbon footprints were quantified using the PAS2050 framework. An activity-based approach was employed to allocate carbon footprints and identify high-emission parts. Based on the allocation results obtained through lifecycle analysis, major components with high carbon emissions were selected. Considering the interplay between carbon emissions and product costs, the paper proposed an improved genetic algorithm that utilized correlation functions to optimize the selected parts, aiming to reduce both carbon footprints and costs. The results demonstrated the effectiveness of the proposed approach in reducing carbon footprints and costs, particularly in the case of pumps.

In another study by Al-Obaidy, Courard, and Attia, sustainable architectural design was optimized using a parametric approach, aiming to bridge the gap between sustainability principles and architectural practice [73]. The approach was tested on a newly constructed office building in Westerlo, Belgium, with a focus on circularity. The environmental impacts of various building systems, including the structural system, foundation type, materials, and envelope details, were evaluated. The study revealed that the use of locally sourced bio-based materials, such as wood, significantly reduced the building’s environmental impact. Sensitivity analysis indicated that factors such as the weight of building materials, potential for material reuse, and the building’s dismantling capacity played a crucial role in achieving carbon-neutral buildings.

It is necessary to define the scope and standards of evaluation to establish an effective carbon-neutral evaluation system. Carbon-neutral design requirements and standards may vary across different regions and countries. Therefore, it is important to reference relevant policy documents, standard specifications, and industry guidelines to ensure that the evaluation system aligns with current regulations and requirements. Furthermore, considering the adoption of internationally recognized evaluation indicators and certification systems can facilitate international comparisons and recognition of evaluation results. In the evaluation process of carbon-neutral building design technologies, data collection, and processing are of paramount importance. Collecting and integrating energy consumption data, material attribute data, environmental data, and other relevant information into the evaluation system is crucial. Additionally, ensuring the accuracy, completeness, and reliability of the data is essential to uphold the credibility and repeatability of the evaluation results.

In conclusion, the evaluation of building carbon-neutral design technologies necessitates the implementation of a multi-criteria system to holistically assess the carbon-neutral performance of buildings. The grey relational analysis algorithm serves as a valuable tool for evaluating these design technologies. Through data processing and analysis, the algorithm quantifies the degree of correlation between different indicators and establishes a relational model among them. This enables the evaluation and comparison of various design options, leading to the selection of an optimal carbon-neutral design solution. When employing the grey relational analysis algorithm, it is crucial to define the evaluation indicators clearly and appropriately process and normalize the indicator data. Indicator selection should encompass energy efficiency, carbon emissions, and building sustainability, aligning with specific evaluation objectives. Data processing involves normalizing the indicator data to ensure consistent units across different indicators, facilitating effective comparison and analysis.

Moreover, it is possible to combine the grey relational analysis algorithm with other evaluation methods and techniques, such as the Analytic Hierarchy Process (AHP) and the fuzzy comprehensive evaluation method. This integration enhances the accuracy and comprehensiveness of the evaluation system. These methods aid in weighing the importance of different indicators, considering their mutual influence, and comprehensively assessing the impact of multiple factors on the carbon-neutral performance of buildings. It is important to acknowledge that the evaluation of building carbon-neutral design technologies is a dynamic process that requires adjustment and optimization to suit the characteristics and requirements of each project. Flexibility and adjustability should be built into the evaluation system to cater to diverse building projects. Additionally, the establishment of the evaluation system should align with relevant policies and standards, ensuring consistency between evaluation results and current regulations and requirements. By constructing a carbon-neutral evaluation system based on the grey relational analysis algorithm, the performance of building carbon-neutral design technologies can be comprehensively assessed, providing scientific evidence and decision support for designers. This will drive the construction industry towards carbon neutrality goals and promote sustainable development.

The building industry is responsible for a substantial portion of global energy consumption and GHG emissions, amounting to roughly 40% of the world’s total carbon emissions. Thus, reducing carbon emissions in this industry is essential to achieving global carbon neutrality goals. Achieving carbon neutrality throughout the FLC of buildings can result in multiple benefits, such as increased building value, reduced operational costs, improved social image and brand influence of enterprises, and promotion of sustainable development in the building industry. Therefore, emphasizing carbon neutrality throughout the FLC of buildings is critical. Specific efforts can be made in the following three areas:

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Carbon emission reduction in the architectural design phase

Effective carbon reduction can be achieved during the architectural design stage by employing appropriate techniques and methods. This paper discusses these techniques and methods in detail through specific research cases. Firstly, the energy efficiency of the building and the feasibility of using clean energy should be considered during the design stage. For instance, Tushar, Bhuiyan, Zhang, amd Maqsood studied a school building with highly energy-saving features using three-dimensional BIM technology [74]. Sensors were used to monitor the indoor environment, and real-time monitoring and analysis of energy consumption data were achieved. The researchers found that technologies such as solar panels, heat recovery units, and heating systems were effective in achieving energy reduction through the analysis of these data. Additionally, Elnabawi delved into the interoperability of the two most widely used energy modeling programs, exploring the challenges of location and weather files, geometric shapes, structures and materials, thermal zones, occupancy schedules, and HVAC systems [75]. After ferreting out all the falsehoods in the interoperability process, they ran benchmark tests on energy modeling simulations based on BIM, comparing them with actual energy consumption in a case study to gauge the reliability of the process. While energy modeling based on BIM presents an exciting prospect for designing sustainable and low-energy buildings, the path from BIM to energy modeling programs remains a non-standardized means of generating building energy models.

Secondly, during the building design phase, it is crucial to consider the use of low-carbon materials and processes to reduce the building’s carbon footprint. For instance, Cordier, Robichaud, Blanchet, and Amor investigated the impact of using wood in buildings on carbon reduction. The researchers found that using wood can reduce the carbon emissions of buildings and contribute to emissions reduction throughout the material’s lifecycle [76]. Moreover, the study explored the environmental impact of wood and sustainable procurement issues, providing guidance for achieving low-carbon buildings. In another study, Pierobon, Huang, Simonen, and Ganguly evaluated the environmental impact from cradle to gate of a commercial building made of cross-laminated timber and compared it to steel-reinforced concrete buildings with similar functional characteristics [77]. The researchers considered two alternative designs for fire protection of cross-laminated timber buildings: fire-resistant design, which applies gypsum wallboard to structural timber, and char design, which adds two additional cross-laminated timber layers to the panel. The results indicated that the global warming potential of cross-laminated timber buildings with mixed mid-rise cross-laminated timber was on average reduced by 26.5% compared to concrete buildings, not including biogenic carbon emissions. This is because wood can absorb carbon dioxide during growth and fix it in the wood, forming a biomass carbon sink, while the production of concrete buildings requires a lot of energy, and the production of its main component, cement, also emits a large amount of carbon dioxide. Therefore, using wood as a building material can reduce carbon emissions during the building’s lifecycle.

In addition, during the architectural design phase, the use of renewable energy sources such as solar and wind power should be considered to reduce the building’s carbon emissions. Del Ama Gonzalo, Moreno Santamaría, and Montero Burgos endeavored to scrutinize several building energy simulation tools to fabricate analogous office units with varying climate conditions in Boston, United States, and Madrid, Spain [78]. The authors initiated an all-encompassing categorization of the tools, ranging from rudimentary online tools with restricted modeling capabilities and inputs to sophisticated simulation engines. After scrutinizing the discrepancies in the outcomes of different software tools, the authors employed cross-validation methods to assess the heating and cooling demands between the tools. The reliability of the simulations was appraised using statistical analysis, and deviation thresholds served as the foundation for determining the results. The results divulged a satisfactory level of disparity between the results of all models, depicting the effectiveness of the analyzed building energy simulation tools.

In conclusion, the reduction of carbon emissions throughout the FLC of buildings is crucial for achieving global carbon neutrality goals. The building industry accounts for approximately 40% of the total global carbon emissions, highlighting the significance of carbon neutrality in building design. The use of energy-efficient and clean energy technologies such as BIM, solar panels, heat recovery systems, and efficient heating systems can improve a building’s energy efficiency and reduce carbon emissions. Low-carbon materials and processes such as sustainable procurement and the use of renewable resources such as wood and bamboo can also reduce the carbon footprint of building construction.

Additionally, renewable energy sources such as solar and wind power can be utilized to provide clean energy and further reduce carbon emissions. Achieving carbon neutrality throughout the FLC of buildings can increase the value of buildings, reduce operational costs, and enhance the social image and brand influence of enterprises while promoting sustainable development. By employing these various technologies and methods in building design, the goal of reducing carbon emissions in the building industry can be achieved.

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Carbon emission reduction in building construction and operation stages

The reduction of carbon emissions in the construction and operation stages of buildings involves various aspects, such as the selection of building materials, optimization of construction processes, and energy-saving measures in building operations. For example, Ma, Hao, Zhang, Di Sarno, and Mannis evaluated the carbon emissions using an LCA method resulting from building and demolition waste generated during a building renovation project in Suzhou City, China [79]. Three waste management schemes were developed, and the results showed that the composition of waste generated from a renovation project was different from that of building and demolition projects. In the lifecycle of waste management in renovation projects, the highest carbon emissions were generated in the renovation material stage, compared to the demolition, renovation construction, and end-of-life stages of renovation materials. In the quest for sustainable and energy-efficient buildings, He, Hossain, Ng, and Augenbroe developed an integrated energy cost model for selecting the best retrofitting solutions for existing high-rise residential buildings in different climatic zones in China [80]. The study involved a comprehensive literature review and analysis of published reports to identify various replacement retrofitting measures for walls, windows, shading systems, heating and cooling systems, and renewable energy technologies. The authors aimed to provide a framework for the selection of cost-effective and sustainable retrofitting measures that can be applied to other countries with different climatic conditions and living standards.

Furthermore, He, Ng, Hossain, and Skitmore proposed a theoretical method to improve the energy efficiency of typical high-rise residential buildings through window retrofitting [81]. They developed a building energy design model in Designbuilder and a building information model in Revit to analyze the energy-saving potential of 20 different types of glass alternatives for a case building with the same orientation located in various climate zones in China. The results indicated that Low-E window glass, though relatively expensive, had the best energy performance in all climate zones. However, its high cost hindered its adoption, despite its energy efficiency being comparable to that of traditional window glass. These findings are crucial in the quest for sustainable and energy-efficient buildings, providing insight into retrofitting measures that can be applied to different climatic zones and living standards.

In conclusion, reducing carbon emissions in the construction and operation stages of buildings can be achieved through various measures, including the use of environmentally friendly building materials and construction processes, as well as optimizing energy-saving measures. For example, the adoption of renewable materials, such as bamboo and hemp, or even waste materials, as well as low-carbon emission building materials such as lightweight concrete and gypsum fiberboard, can help to reduce the carbon footprint of construction materials. Low-carbon construction techniques, such as the use of green building technologies that include low-carbon cement, geothermal energy, and solar energy, can also be employed.

Additionally, energy-saving measures, including the use of high-efficiency equipment and technology such as lighting and air conditioning systems, can be implemented during building operations. Automated control systems and equipment usage optimization can also help reduce energy use in building operations. Monitoring and analyzing energy use through sensors and other technologies can enable real-time optimization of energy use and management. In summary, the use of environmentally friendly building materials, optimized construction processes, energy-saving measures, and energy use monitoring and analysis are effective ways to achieve carbon reduction during both the construction and operation stages of buildings.

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Carbon reduction in the demolition and abandonment phase of buildings

In the phase of demolition and disposal of buildings, carbon emission reduction mainly involves waste disposal and reuse, building material recycling and reuse, and green demolition. For instance, Cha et al. surveyed 1034 residential buildings in South Korea prior to demolition to collect reliable information on demolition waste generation rates [82]. They divided the demolition phase into three stages: demolition, collection and sorting, and transportation and disposal, and calculated the economic value of recycled demolition waste materials. In the best-case scenario, masonry structures showed higher recycling potential. In terms of types of demolition waste, plastic had the highest potential for recycling, and the plastic from reinforced concrete structures had 6.6 times the recycling potential of that from wooden structures. The possibility of increasing the recycling potential of glass and plastic was higher than that of aggregates, wood, and metals.

Liu, Huang, and Wang undertook an intricate study to investigate the potential environmental and economic impacts of various waste disposal scenarios in Guangzhou, China, while taking into account the impact of carbon trading [83]. The study employed a combination of lifecycle assessment and lifecycle costing to assess the carbon emissions of demolition waste and to determine the cost of carbon emissions based on Guangdong Province’s carbon trading market. The three waste disposal scenarios examined were S1 (landfill), S2 (recycled aggregate), and S3 (recycled powder). The results demonstrated that recycling waste can significantly mitigate carbon emissions. The study is remarkable for its novel exploratory method that factored in both environmental and economic benefits. This approach could guide the development of new policies for demolition waste management. In addition, given the implementation of carbon trading, this study can also offer new insights into current demolition waste treatment from both economic and environmental perspectives.

In summary, carbon reduction during the demolition and disposal stages of buildings can be achieved through a variety of measures, such as waste handling and reuse, building material recovery and reuse, green demolition, and early planning and design. Waste handling and reuse involve classifying and reusing the large amounts of waste produced during demolition to effectively reduce environmental pollution and save new materials, thereby lowering carbon emissions. Building material recovery and reuse involve adopting recovery and reuse strategies for materials such as metal and glass to reduce the consumption of new materials and the generation of waste, resulting in decreased carbon emissions. Green demolition involves utilizing low-carbon, environmentally friendly demolition processes and equipment, such as electric demolition machines, to reduce energy consumption and environmental pollution, thus reducing carbon emissions. Early planning and design involve adopting removable and reusable design strategies during the early planning and design stages of buildings while considering the subsequent disposal of demolished materials to reduce carbon emissions during demolition and disposal. These measures can effectively reduce carbon emissions during the demolition and disposal processes of buildings while promoting efficient resource use and environmental protection.

6. Conclusions and Prospects of Key Scientific Issues in Carbon-Neutral Design for Buildings

This study intuitively presents the current status and development trends of building carbon neutrality design through the use of econometric analysis, and focuses on design methods, evaluation, and quantitative research. The quantity and quality of literature publications can reflect the development speed of and yearly progress in carbon neutrality-related research in construction. In the research on the proportion and content of publications in the top five journals, it is shown that domestic building carbon neutrality design focuses on its integration with urban planning and development in the energy field. The analysis of keywords shows that keywords such as carbon neutrality, peak carbon dioxide emissions, carbon reduction, climate change, and carbon emissions play a strong mediating role and have a more significant impact. In addition, keyword cluster analysis shows that building carbon neutrality research focuses on understanding “greenhouse gases”, focusing on measuring “building carbon emissions”, improving carbon neutral design, and building a low-carbon economy circle and industrial chain. The cooperation shows the strong cooperation between institutions and countries. China, the United States and the United Kingdom are the three leading countries with the largest number of publications, and, in China, the Chinese Academy of Sciences (CAS) is the institution with the highest output of published papers among research institutions. The results of keyword time evolution analysis show that the emerging research frontiers and hotspots of building carbon neutral design focus on building carbon cycle economy, zero-energy building design, energy self-sufficient buildings, and building carbon capture and utilization.

At present, the concept and standards of carbon neutrality are not yet clear, and reliable measurement and evaluation are challenging. Therefore, the article explores the development of a more accurate definition of the scope and standards of carbon neutrality. On this basis, a more detailed study will be conducted on the sources, quantification methods, and evaluation of building carbon emissions. Significant progress has been made in the field of building carbon neutral design, including progress in carbon footprint assessment methods, green building materials, building energy-saving technologies, renewable energy utilization technologies, and sustainable development. In terms of carbon neutrality assessment methods, the selection of carbon footprint assessment methods should be based on such factors as assessment objects, data availability and accuracy requirements. It is an important tool for assessing the carbon emissions of buildings throughout their entire lifecycle, including construction, use, and demolition. Grey correlation analysis is a commonly used evaluation method in multi criteria systems, which comprehensively considers various aspects of building energy efficiency, carbon emissions, and sustainability.

The future direction of building carbon neutrality design should promote sustainability and environmental friendliness by achieving efficient carbon neutrality. The future direction of carbon-neutral design for buildings should prioritize achieving efficient carbon neutrality while promoting sustainability and environmental friendliness. As science and technology continue to advance, carbon-neutral design for buildings will become more intelligent, automated, and digitized. Artificial intelligence technology can be utilized in building energy management systems to achieve more precise and smart energy regulation. New materials and technologies can be employed to improve carbon capture efficiency and utilization value. The relationship between buildings and urban environments can be explored to optimize urban ecology and promote sustainable development. Furthermore, low-carbon development demands and pressures from governments and society will continue to drive the development and application of carbon-neutral design for buildings.