Search Results (369)

The global climate crisis has driven unprecedented agreements among nations on carbon mitigation. With China’s commitment to carbon peaking and carbon neutrality targets, the building sector has emerged as a critical focus for emission reduction, particularly because office buildings account for over 30% of building energy consumption. However, a systematic and regionally adaptive low-carbon technology evaluation framework is lacking. To address this gap, this study develops a multidimensional decision-making system to quantify and rank low-carbon technologies for office buildings in Beijing. The method includes four core components: (1) establishing three archetypal models—low-rise (H ≤ 24 m), mid-rise (24 m < H ≤ 50 m), and high-rise (50 m < H ≤ 100 m) office buildings—based on 99 office buildings in Beijing; (2) classifying 19 key technologies into three clusters—Envelope Structure Optimization, Equipment Efficiency Enhancement, and Renewable Energy Utilization—using bibliometric analysis and policy norm screening; (3) developing a four-dimensional evaluation framework encompassing Carbon Reduction Degree (CRD), Economic Viability Degree (EVD), Technical Applicability Degree (TAD), and Carbon Intensity Degree (CID); and (4) conducting a comprehensive quantitative evaluation using the AHP-entropy-TOPSIS algorithm. The results indicate distinct priority patterns across the building types: low-rise buildings prioritize roof-mounted photovoltaic (PV) systems, LED lighting, and thermal-break aluminum frames with low-E double-glazed laminated glass. Mid- and high-rise buildings emphasize integrated PV-LED-T8 lighting solutions and optimized building envelope structures. Ranking analysis further highlights LED lighting, T8 high-efficiency fluorescent lamps, and rooftop PV systems as the top-recommended technologies for Beijing. Additionally, four policy recommendations are proposed to facilitate the large-scale implementation of the program. This study presents a holistic technical integration strategy that simultaneously enhances the technological performance, economic viability, and carbon reduction outcomes of architectural design and renovation. It also establishes a replicable decision-support framework for decarbonizing office and public buildings in cities, thereby supporting China’s “dual carbon” goals and contributing to global carbon mitigation efforts in the building sector. Full article

Offsite construction (OSC) offers a promising alternative for accelerating refurbishment projects across Italy and Europe. However, its adoption remains limited due to technical, regulatory, and cultural barriers. This study, conducted as part of the OFFICIO project, maps the current European OSC landscape, with a focus on wood and light-steel technologies for sustainable building refurbishment. Combining a literature review, analysis of funded projects, and market data for 541 OSC products, the study develops tailored KPIs to assess these products’ technical maturity, prefabrication level, and environmental integration. The results reveal that wood-based OSC, although less widespread, is more mature and centered on the use of multi-layer panels, while steel-based systems, though more prevalent, remain largely tied to semi-offsite construction, indicating untapped development potential. Research efforts, especially concentrated in Mediterranean regions, focus on technological integration of renewable energy systems. A significant literature gap was identified in information concerning panel-to-wall connection, critical for renovation, limiting OSC’s adaptability to regeneration of existing buildings. The findings highlight the need for cross-sector collaboration, legislative clarity, and better alignment of public procurement standards with OSC characteristics. Addressing these issues is essential to bridge the gap between research prototypes and industrial adoption and accelerate the sustainable transformation of Europe’s construction sector to help meet climate neutrality targets. Full article

Heritage building conservation plays a special role in addressing modern sustainability challenges by preserving the cultural identity, retrofitting, restoring, and renovating these structures to improve energy performance, which is crucial for revitalisation. This research aims to use Heritage Building Information Modelling (HBIM) to increase energy efficiency and environmental sustainability in historic buildings. Retrofitting heritage buildings presents unique challenges and opportunities to simultaneously reduce energy consumption and carbon emissions while maintaining historical integrity. Traditional approaches are often insufficient to meet heritage structures’ energy needs. Modern technologies such as information building modelling and energy simulations can offer solutions. HBIM is a vigorous digital framework that facilitates interdisciplinary collaboration and offers detailed insights into building restoration and energy modelling. HBIM supports the integration of thermal and energy efficiency measures while maintaining the authenticity of heritage architecture by creating a comprehensive database. Using a case study heritage building, this research demonstrates how retrofitting the different aspects of heritage buildings can improve energy performance. Evaluating the preservation of heritage buildings’ cultural and architectural values and the effectiveness of using HBIM to model energy performance offers a viable framework for sustainable retrofitting of heritage buildings. Full article

The architectural, engineering, construction, and operation (AECO) sector is one of the main contributors to energy consumption and greenhouse gas emissions in Europe, making the renovation of the existing building stock a priority. However, defining effective and economically sustainable interventions remains a challenge, partly due to the variability of building characteristics and the lack of digital tools to support data-driven decision making. This research aims to identify the main factors influencing the energy consumption of buildings by analyzing a large database of building characteristics using machine learning algorithms. Based on the parameters that the analysis shows to have the greatest impact, the average cost of energy retrofitting measures will be used to elaborate a cost–benefit analysis model and the economic payback time for each measure, individually or in combination. The expected result is the creation of a tool that will allow the operator to evaluate the choice of interventions based on the energy efficiency that can be achieved and/or the economic sustainability. The proposed methodology aims to provide a digital approach that is replicable and adaptable to different territorial realities and useful for strategic planning of energy transformation in the building sector. Full article

This study investigates the deployment of VERIFY, a dynamic life cycle assessment (LCA) and life cycle costing (LCC) tool, tailored to evaluate the energy and environmental performance of building renovation strategies. The tool was applied to three diverse building renovation projects across Europe, offering insights into how life cycle-based tools can enhance decision-making by integrating operational data and modeling of energy systems. The paper highlights how VERIFY captures both embodied and operational impacts—addressing limitations of conventional energy assessments—and aligns with EU frameworks such as Level(s). Key findings from the case studies in Italy, Spain, and the Netherlands demonstrate how LCA/LCC-based approaches can support energy efficiency objectives and guide sustainability-aligned renovation investments. Across the three case studies, the tool demonstrated up to 51% reduction in primary energy demand, 66% decrease in life cycle greenhouse gas emissions, and 51% reduction in life cycle costs. These outcomes provide researchers with a validated dynamic LCA/LCC framework and offer practitioners a replicable methodology for planning and evaluating sustainability-driven renovations. Despite their advantages, the effective use of LCA tools in energy renovation faces challenges, including limited data availability, regulatory fragmentation, and methodological complexity. The paper concludes that advanced tools such as VERIFY, when harmonized with evolving EU energy performance and sustainability standards, can strengthen the evidence base for deep energy renovation and carbon reduction in the building sector. Full article

China’s urban residential building stock is extensive and spans a wide range of construction periods. With the continuous enhancement of building energy efficiency standards, the chronological characteristics and variability of residential building envelopes are evident. Through field research and typological analysis of residential buildings in Jinan, a cold region of China, three construction eras were classified: Period I (1980–1985), Period II (1986–1995), and Period III (1996–2005). Building performance and economic benefits across these periods are modeled using Rhino 7.3 and Grasshopper. The NSGA-II algorithm, as the core of Wallacei2.7, is employed for multi-objective optimization. Through K-means clustering, TOPSIS comprehensive ranking, and Pearson correlation analysis, the optimized processes and solutions are provided for urban residential renovation decisions in different periods and target preferences. The results show that the optimal comprehensive performance solutions for Period I, Period II, and Period III achieve energy savings of 40.92%, 29.62%, and 15.81%, respectively, and increase annual indoor comfort hours by 872.64 h/year, 633.57 h/year, and 564.11 h/year. For Period I and II residential buildings, the most effective energy efficiency retrofit measures include increasing exterior wall and roof insulation, replacing exterior window types, and reducing exterior window k-value. The overall trend in energy savings rates and economic benefits across the three periods shows a decline. For Period III residential buildings, systematic strategies, such as solar thermal collector systems and photovoltaic technology, are required to enhance energy efficiency. Full article

Energy retrofitting of historic buildings presents complex challenges, particularly when using internal insulation strategies. While such interventions can enhance thermal comfort and reduce energy demand, they can also pose risks of condensation and mold formation, thereby reducing usable space. This paper proposes an evaluation methodology for assessing the performance of internal insulating panels within a multicriteria framework to support decision-making during the design phase. The approach, scalable to various contexts, is grounded in a digital workflow that integrates heritage building information modeling (HBIM), visual programming (VP), and building energy modeling (BEM) to create a decision-support tool for renovation designers. The methodology, tested on a building located in Bologna (Italy), allows for assessing internal insulation systems with varying thermophysical properties and performance characteristics, and evaluating how they affect space- and wall-level key performance indicators, including condensation risk, energy efficiency improvement, and usable space reduction. The research was conducted under the Horizon Europe HERIT4AGES project, which aims to develop reversible, innovative insulation panels fabricated from local and recycled materials for historic building retrofitting. Full article

In the current context, where sustainability, energy efficiency, and reduction of environmental impact are omnipresent themes, the need and interest for conservation, restoration, and reuse of heritage buildings is a topic of real interest. The city of Oradea, engaged in the last decades on the path of a sustainable urban regeneration, has managed to bring back to life part of the valuable Art Nouveau architectural treasure it inherited from previous generations. This paper presents a part of a much wider research and studies on Art Nouveau buildings in Oradea, in the context of the needs arising from the many problems identified with the start of conservation and restoration works. After an introduction on the link between heritage buildings and sustainability and a review of the current context in Oradea related to this topic, one of the emblematic buildings under renovation, the Ullmann Palace, is presented, as well as the results of some physical-mechanical tests carried out. This is followed by some discussions on the innovative and sustainable character of Art Nouveau buildings and the importance of carrying out high-quality conservation and restoration works that are environmentally friendly, safe, and sustainable. Full article

Achieving both indoor environmental quality (IEQ) and energy efficiency in school buildings remains a challenge, particularly in older structures where renovation strategies often lack site-specific validation. This study evaluates the impact of energy retrofits on a 1970s primary school in France by integrating in situ measurements with a validated numerical model for forecasting energy demand and IEQ. Temperature, humidity, and CO₂ levels were recorded before and after renovations, which included insulation upgrades and an air handling unit replacement. Results indicate significant improvements in winter thermal comfort (PPD < 20%) with a reduced heating water temperature (65 °C to 55 °C) and stable indoor air quality (CO₂ < 800 ppm), without the need for window ventilation. Night-flushing ventilation proved effective in mitigating overheating by shifting peak temperatures outside school hours, contributing to enhanced thermal regulation. Long-term energy consumption analysis (2019–2022) revealed substantial reductions in gas and electricity use, 15% and 29% of energy saving for electricity and gas, supporting the effectiveness of the applied renovation strategies. However, summer overheating (up to 30 °C) persisted, particularly in south-facing upper floors with extensive glazing, underscoring the need for additional optimization in solar gain management and heating control. By providing empirical validation of renovation outcomes, this study bridges the gap between theoretical predictions and real-world effectiveness, offering a data-driven framework for enhancing IEQ and energy performance in aging school infrastructure. Full article

In this work, the indoor thermal environment and indoor air quality of rural houses in Northern China were investigated in detail. The current heating situation in rural areas, the causes of indoor air pollution, and the indoor ventilation habits of residents were analyzed. The indoor thermal environment and indoor air quality were improved by upgrading the thermal insulation of the rural housing envelope and installing indoor ventilation systems with heat recovery, leading to an average indoor temperature increase of 6 °C. The Predicted Mean Vote reached approximately 1.0, so the human body heat sensation was more moderate. The air age was greatly reduced, and the indoor air quality was significantly improved. The Predicted Percentage of Dissatisfied dramatically decreased to 15%. Thus, when focusing on heat source renovation in rural areas, priority should be given to improving the energy efficiency of buildings, especially the building envelope insulation performance. Ventilation and air exchange systems with heat recovery are inexpensive and effective, and they are suitable for rural dwellings where the temperatures are not as high as they should be but where the indoor air quality is poor and ventilation is urgently needed. Full article

The digital transition and decarbonization are strategic European objectives, supported at different levels by the Green Deal, the Energy Performance Building Directive (EPBD), and policies and tools such as the Energy Performance Certificate (EPC) and the Smart Readiness Indicator (SRI). The SRI measures a building’s ability to use intelligent technologies to reduce its consumption and increase the energy awareness of occupants for energy efficiency. Furthermore, today, it has a limited impact on national regulations and public decision-making. Its application presents challenges including those related to heritage conservation. This paper contributes to the Italian SRI framework through an experimental application in the renovation of a historic building in the metropolitan city of Reggio Calabria (Italy). The analysis evaluates the SRI’s adaptability by comparing its pre-renovated state, current state, and pre-design plan. The SRI calculation integrates assessment tools with BIM models for a potential future digital twin approach. The study, part of a funded national research project, aims to enhance policies for digitalization in the green transition. The paper is organized into the Introduction; Materials and Methods, which contains the methodological approach; Results; and Discussion and Conclusions. Following the experimental application, the results show that standardizing the SRI approach could enhance energy efficiency and digitalization in buildings. Full article

In the European Union, 75% of the residential building stock is estimated to have energy inefficiencies, which increases the probability of falling into energy poverty. Poor thermal conditions reduce the quality of life of dwelling occupants. Renovating the residential building stock is essential to reduce energy consumption, CO₂ emissions, and energy poverty in cities. This study aims to assess and map the energy efficiency and energy poverty of residential buildings in Seville at the urban district and census tract level. A total of 45,908 dwellings were evaluated using data from the Energy Performance Certificates database and demographic and economic information from national and official databases. The analysis considers dwelling typology, year of construction, average household income, and geographic location at the district and census tract level. The results show that Seville’s residential building stock performs poorly, with 83% and 92% of dwellings rated “E” or lower for energy consumption and CO₂ emissions, respectively. The findings of this GIS-based study help identify urban areas with less efficient buildings and higher energy poverty risk, providing valuable information to develop targeted renovation strategies and reduce the climate impact of Seville’s residential building stock. Full article

The current climate and energy crises demand innovative approaches to operating buildings more sustainably. HVAC systems, which significantly contribute to a building’s energy consumption, have been a major focus of research aimed at improving operational efficiency. However, a critical factor often overlooked is the seasonal and hourly variation in solar radiation and the resulting solar heat gain, which heats specific rooms differently depending on their orientation, type, and location within the building. This study proposes a simulation-based strategy to reduce HVAC energy use in hotels by allocating guests to rooms with more favorable thermal characteristics depending on the season. A high-resolution building energy model (BEM) was developed to represent a real 17-floor hotel tower in Madrid, incorporating detailed geometry and surrounding shading context. The model includes 439 internal thermal zones and simulates solar radiation using EnergyPlus’ Radiance module. The simulation results revealed large room-by-room differences in thermal energy demand. When applying an energetically optimized guest allocation strategy based on these simulations and using real occupancy data, potential reductions in HVAC energy demand were estimated to reach around 6% during summer and up to 20% in winter. These findings demonstrate that data-driven guest allocation, informed by physics-based building simulations, can provide substantial energy savings without requiring physical renovations or equipment upgrades, offering a promising approach for more sustainable hotel operation. Full article

This work presents an on-field noise analysis during the class breaks in Greek school units (a high school and a senior high school) based on the design and deployment of low-cost IoT sensor nodes and IoT platforms. The course breaks form 20% of a regular school day, during which intense mobility and high noise levels usually evolve. Indoor noise levels, along with environmental conditions, have been measured through a wireless network that comprises IoT nodes that integrate humidity, temperature, and acoustic level sensors. PM₁₀ and PM_2.5 values have also been acquired through data sensors located nearby the school complex. School buildings that have been recently renovated for minimizing their energy footprint and CO₂ emissions have been selected in comparison with similar works in academia. The data are collected, shipped, and stored into a time-series database in cloud facilities where an IoT platform has been developed for processing and analysis purposes. The findings show that low-cost sensors can efficiently monitor noise levels after proper adjustments. Additionally, the statistical evaluation of the received sensor measurements has indicated that ubiquitous high noise levels during the course breaks potentially affect teachers’ leisure time, despite the thermal isolation of the facilities. Within this context, we prove that the proposed IoT Sensor Network could form a tool to essentially monitor school infrastructures and thus to prompt for improvements regarding the building facilities. Several guides to further mitigate noise and achieve high-quality levels in learning institutes are also described. Full article

This study constructs a system dynamics (SD)-based energy efficiency model for retrofitting existing residential buildings by considering urban residential buildings in Liaoning Province, China. In this study, we sorted the boundaries of building energy efficiency accounting, analyzed the current status of related research and system dynamics theory, determined the influencing factors and transmission mechanisms of residential building energy efficiency renovation, set the research boundaries and assumptions, drew the circuit diagrams of various subsystems, determined the main equations and parameters of the model, and ensured the reliability of the model through stability and historicity tests. Through scenario simulation and analysis, it was found that, from 2016 to 2035, the comprehensive benefits of urban residential building renovation will grow slowly in the early stage and rapidly in the late stage, which will potentially have large benefits. The socio-economic environment, governmental policies, energy-saving technologies, market demand, and other factors influence each other, among which the progress of energy-saving technologies has the greatest impact on the comprehensive benefits. Changing the inputs of a certain aspect cannot make the benefits of energy consumption, environment, and economic tripartite grow equally. The energy consumption benefit potential of centralized heating renovation is larger. The results of this study provide a theoretical basis and decision support for the energy-saving transformation of existing residential buildings. Full article