Search Results (54)

Improving resource efficiency by reducing waste and process inefficiencies across the building life cycle is essential for advancing sustainability in the built environment. Circular and industrialized construction offer complementary strategies to meet this challenge. While Design for Manufacturing and Assembly (DfMA) enhances constructability, standardization, and productivity in early project phases, Design for Disassembly (DfD) facilitates material recovery and adaptability at end-of-life. Despite their synergies, their integrated application remains underexplored. This study proposes a unified framework—Design for Manufacturing, Assembly, and Disassembly (DfMAD)—to align value creation and value retention strategies across the life cycle. A systematic literature review of 102 articles, following PRISMA guidelines, combined bibliometric and thematic analysis to identify key principles, benefits, barriers, and enablers of DfMA and DfD. Cross-mapping these findings revealed conceptual overlaps and distinctions and informed the synthesis of core DfMAD attributes. The resulting framework offers a life cycle-oriented approach that supports product-based delivery, traceability, and circular design strategies. By promoting shared logic across disciplines and project phases, DfMAD provides a foundation for operationalizing circularity in industrialized construction, contributing both theoretical and practical guidance for advancing resource-efficient, adaptable, and disassemblable building systems. Full article

Offsite construction (OSC) is fragmented and involves a complex network of stakeholders in all the stages such as planning, design, legal approval, site preparation, modular manufacturing, transportation, storage, and onsite installation. The barriers include complexity of the process; lack of awareness; supply chain challenges in capacity and knowledge; cultural perception; lack of viable business process models or solutions; scarcity of skills in design/manufacturing/construction and lack of government regulations and legislation. This study, therefore, categorises the barriers according to political, economic, social, technological, environmental, and legal (PESTEL) analysis. The PESTEL analysis aims at providing organisations a comprehensive list of all the external barriers against the adoption of offsite construction. A wholistic list of all the barriers and understanding the barriers will help them to improve the overall productivity and contribute to the economy metrics. Utilising popular databases, including Scopus, Web of Science, and Google Scholar, a systematic literature review of 56 papers relevant to OSC adoptions in the construction industry research was conducted. From the review, the barriers to the adoption of OSC in the construction research and relevant organisations reports were identified. The research shows that countries such as Australia, UK, China, Hong Kong, Singapore, and New Zealand have been the top countries in which papers on OSC were published. A relationship analysis shows that political barriers amounting to 5 out of the 101 barriers identified having the most causal effects on the low adoption of OSC. Full article

Modular construction has the potential to transform the construction industry, as most (80–95%) of the modules, which are considered prefabricated buildings, are manufactured off-site, which is more efficient, safe, cost-effective, sustainable, productive, and faster than traditional construction. It is not without challenges, however, as it requires detailed and comprehensive planning, high initial costs, and navigating transportation and design constraints. The goal of this study was to identify and categorize the benefits and challenges of modular construction and offer strategies for resolving the challenges. This study also provides a comprehensive review of modular construction methods, including permanent modular construction (PMC), movable modular construction (RMC), volumetric modular construction (VMC), and panelized construction, and examines the connectivity of the modules, as well as the integration of advanced technologies like artificial intelligence (AI). The results revealed that the most frequently cited benefits of modular construction were reducing construction time by up to 50%, 20% cost savings, and material waste reduction of up to 83%. The most common challenges included transportation complexity, limited design flexibility, and high initial costs. The results of this study will assist project managers, construction professionals, and company owners in evaluating modular construction by providing quantified benefits and challenges, a comparative analysis of different modular methods, and insights into effective mitigation strategies, allowing them to assess its suitability based on project timelines, budgets, design requirements, and logistical constraints. Full article

The industrial sector’s increasing electricity demand (direct and indirect), driven by the electrification of processes and the production of green hydrogen, poses significant challenges for achieving decarbonisation goals. While switching to renewable electricity and offsetting emissions appears straightforward, the gap between current generation capacities and projected demand remains substantial. This article analyses survey data from the Energy Efficiency Index of German Industry (EEI), revealing that manufacturing companies aim to reduce 22.1% of their 2019 emissions by 2025 and 27.3% by 2030, primarily through on-site measures. However, given the slow pace of renewable capacity expansion and the increasing electrification across sectors, it becomes evident that the envisaged green electricity share of 80% by 2030 will require far more capacity than currently planned. To address this challenge, the article introduces a decarbonisability factor to better assess on-site versus off-site measures, highlighting the need for a strategic sequencing of efficiency and renewable generation. To support decision-makers, the article calls for improved data collection and periodic reassessment to account for changing geopolitical and economic conditions. Full article

Earthen construction is one of the earliest and most ubiquitous forms of building. Compressed stabilized earth blocks (CSEBs) combine compressed components including inorganic soil, water, and a stabilizer such as Portland cement, and can achieve greater strength than other earthen construction methods. Typically, site-specific soil comprises the bulk material in CSEB construction, which minimizes the quantity of construction materials that need to be provided from off-site and motivates this type of building material for remote locations. However, onsite manufacturing and innate soil variability increase the variability of CSEB mechanical properties compared to more standardized building materials. This study characterizes the effects of varying mix compositions and initial compressions on the density, compressive strength, and variability of compressed stabilized earth cylinders (CSECs) created from sandy soil. CSEC samples comprising nine mix compositions and four levels of initial compression provide data for the (i) statistical evaluation of strength, density, and variability and (ii) development of predictive equations for density and compressive strength, with R² values of 0.90 and 0.89, respectively. Full article

Precast concrete structures have become increasingly popular in the construction industry due to their ability to enhance efficiency, structural soundness, quality, and sustainability. Among these, modular construction has emerged as a transformative approach that fully leverages precast technology by manufacturing 3D modules off-site and assembling them on-site using inter-module connections. This study reviewed current literature trends on precast concrete structures and modular construction, analysing how modular construction distinguishes itself from other precast systems. This review further emphasises the role of composite connections—grouted, bolted, and hybrid systems—critical in ensuring structural integrity, efficiency in load transfer, and seismic resilience in modular construction. Advancements in composite connections have demonstrated significant promise, particularly in seismic performance, with reported energy dissipation improvements of up to 30% in hybrid connection systems. Yet limitations still exist, necessitating improvements in load transfer efficiency, ductility, and reliability under dynamic loads. Additionally, design considerations for modular construction, such as modular configurations, handling stresses, and transportation challenges, are explored to highlight their influence on system performance. This review underscores the feasibility and potential of modular construction in fostering sustainable and resilient infrastructure, as studies indicate that modular construction can reduce project timelines by up to 50% while minimising material waste by approximately 30%. The role of Non-Destructive Evaluation (NDE) techniques and intelligent monitoring systems in assessing and enhancing the lifecycle performance of composite connections is also emphasised. This review further advocates for continued research to refine composite connections and support the broader adoption of modular construction in modern building practices. Full article

The construction industry continues to face challenges such as increased costs, time overruns, and low quality. Off-site construction (OSC) methods are increasingly being adopted as alternatives to traditional construction practices to address these issues, with off-site manufacturing (OSM) representing a key difference in construction methods. However, existing studies have largely neglected the systematic evaluation of OSM risks on quality, cost, and delivery (QCD) outcomes, leaving a significant gap in understanding the complex interdependencies among risk factors. To improve risk management in OSC projects, it is crucial to evaluate the impact of OSM risks on QCD outcomes. This study applies the Bayesian Belief Network (BBN) method to develop an evaluation model that measures the impact of OSM risks on QCD outcomes in OSC projects. The results identify 12 significant risk factors affecting QCD outcomes in OSC projects. Five key risk groups were identified as critical for managing OSM risks. This approach provides a systematic framework for managing OSM risks and optimizing OSC practices in China. Full article

The traditional construction industry is characterized by high energy consumption and significant carbon emissions, primarily due to its reliance on on-site manual labor and wet operations, which are not only low in mechanization but also result in low material efficiency and substantial construction waste. Prefabricated construction offers a new solution with its efficient production methods, significantly enhancing material utilization and construction efficiency. This paper focuses on the production scheduling optimization of prefabricated components. The production scheduling directly affects the construction speed and cost of prefabricated buildings. Given the complex modeling and numerous constraints faced by the production of prefabricated components, we propose an improved Non-dominated Sorting Genetic Algorithm II (NSGA-II) for multi-objective optimization. The algorithm incorporates adaptive operators and greedy concepts for local search, enhancing solution exploration and diversity. We segment the production of prefabricated components into six stages, analyzing dependencies and constraints, and form a comprehensive scheduling model with objectives of minimizing contract penalties, storage costs, and production time. Extensive experiments demonstrate that the improved NSGA-II provides a more balanced and larger set of solutions compared to baseline algorithms, offering manufacturers a wider range of options. This research contributes to the optimization of production scheduling in the prefabricated construction industry, supporting coordinated, sustainable, automated, and transparent production environments. Full article

Stakeholder management is a crucial component in the implementation of off-site construction (OSC) projects, while stakeholder mapping serves as a practical technique to facilitate an in-depth understanding of different project stakeholders. Various topics have been explored in the OSC stakeholder management field, but research on OSC stakeholder analysis based on stakeholder mapping is still lacking. This study addresses this gap by developing two-dimensional (2D) and three-dimensional (3D) stakeholder mapping models. Data were collected from 167 stakeholders involved in OSC projects. The 2D model utilizes a power–interest matrix to classify 12 identified OSC stakeholder groups, while the 3D model further explores these groups by incorporating an additional dimension of stakeholder salience across different stages of project implementation. The results show that OSC stakeholders predominantly fall into the “key players” or “minimal effort” categories across various project stages. Key players include the client, modular manufacturer, main contractor, government, and designer, while the public and industry organizations generally require minimal effort. Additionally, stakeholders such as the supervision company, supplier, and subcontractor play key roles at specific stages, with varying levels of salience throughout the project lifecycle, reflecting shifts in their influence and involvement. The findings contribute to stakeholder management knowledge by providing an in-depth understanding of OSC stakeholders’ interrelationships during project implementation, especially through uncovered stakeholder mapping in the OSC field. Full article

Off-site construction is well-known technology that facilitates parallel processes of manufacturing and construction processes. This method enhances productivity while reducing accident, cost, and environmental impact. Many studies have highlighted its benefits, prompting further encouragement of off-site construction. This study consolidates current research and charts future directions by reviewing the existing literature. However, reviewing papers is time-intensive and laborious. Consequently, generative AI models, particularly Large Language Models (LLMs), are increasingly employed for document summarization. Specifically, LangChain influences LLMs through chaining data, demonstrating notable potential for research paper reviews. This study aims to evaluate the well-documented advantages of off-site construction through LangChain integrated with an LLM. It follows a streamlined process from the collection of research papers to conducting network analysis, examining 47 papers to uncover that current research primarily demonstrates off-site construction’s superiority through cutting-edge technologies. Yet, a data deficiency remains a challenge. The findings demonstrate that LangChain can rapidly and effectively summarize research, making it a valuable tool for literature reviews. This study advocates the broader application of LangChain in reviewing research papers, emphasizing its potential to streamline the literature review process and provide clear insights into off-site construction’s evolving landscape. Full article

To select the optimal design alternative in off-site construction (OSC) projects, the building industry has turned to design for manufacturing and assembly (DfMA). However, most DfMA developments in the OSC field until now have been on improving the production process in OSC projects and guideline strategies on how to apply them. The application of DfMA guidelines only provides background knowledge to designers on how to design. However, it cannot inspect whether the DfMA concept is fully reflected in a design draft to examine the suitability to the OSC production environment, and it cannot determine the optimal alternative from among multiple design alternatives. Thus, this study developed an integrated assessment model of OSC-DfMA consisting of the OSC-DfMA production suitability assessment model and the OSC-DfMA production efficiency assessment model to support decision-making for selecting the optimal design alternative of an OSC project. In this study, the scope of the main research was limited to precast concrete (PC)-based OSC projects. Firstly, we developed an OSC-DfMA production suitability assessment model to review whether design drafts are suitable in the OSC production environment by applying checklist and matrix techniques. Secondly, we developed an OSC-DfMA production efficiency assessment model to select an optimal alternative in terms of production efficiency among multiple design drafts. Thirdly, we conducted a case study to validate the usefulness of the OSC-DfMA assessment model developed in this study. Finally, we discuss the possibility of using AI technology to consider the facility capacity and resource constraints during the production of OSC building components. The study results are of practical value in providing the basis for expanding the applicability of DfMA by proposing a DfMA assessment model suitable for OSC contexts. Full article

A reasonable allocation of production schedules and savings in overall electricity costs are crucial for large manufacturing conglomerates. In this study, we develop an optimization model of off-site industrial production scheduling to address the problems of high electricity costs due to the irrational allocation of production schedules on the demand side of China’s power supply, and the difficulty in promoting industrial and commercial distributed photovoltaic (PV) projects in China. The model makes full use of the conditions of different PV resources and variations in electricity prices in different places to optimize the scheduling of industrial production in various locations. The model is embedded with two sub-models, i.e., an electricity price prediction model and a distributed photovoltaic power cost model to complete the model parameters, in which the electricity price prediction model utilizes a Long Short-Term Memory (LSTM) neural network. Then, the particle swarm optimization algorithm is used to solve the optimization model. Finally, the production data of two off-site pharmaceutical factories belonging to the same large group of enterprises are substituted into the model for example analysis, and it is concluded that the optimization model can significantly reduce the electricity consumption costs of the enterprises by about 7.9%. This verifies the effectiveness of the optimization model established in this paper in reducing the cost of electricity consumption on the demand side. Full article

Construction professionals work in silos and use traditional design and construction methods. The growing demand for rapidly built and high-quality construction is making off-site manufacturing mainstream. Studies have shown that collaboration among all stakeholders is a necessary component for success in the construction of such buildings. This multidisciplinary study of an existing concrete hotel aims to explore an alternative structural design in mass timber or volumetric modular construction. To this end, the reinforced concrete floor plan of Club Med de Charlevoix in Quebec, Canada, was used as a benchmark for two different structural systems. The first strategy investigated CLT (cross-laminated timber) and glulam columns to replicate the reinforced concrete system (column–slab), while the second involved maximum prefabrication (volumetric modular construction). Both mass timber and volumetric modular strategies can lead to a smaller carbon footprint. The main conclusion is that the plan should be designed from the outset to be either traditional or prefabricated since major changes are required if the choice is made to switch from one system to the other. Moreover, when structural systems maximize off-site construction, such as volumetric modular construction, the various professions need to be included during early planning. This is necessary to avoid task duplication and prevent the neglect of considerations such as manufacturable dimensions and partition organization. Full article

The construction industry in New Zealand is significantly impacted by the importance of housing, particularly as urbanisation continues to grow in major cities. Modern construction methods, such as offsite construction and building automation, evolving into digital manufacturing and construction in the industry, have become prominent. Despite the global recognition of 3D printing technology, its adoption in the construction industry in New Zealand is still relatively limited. This study aims to examine the feasibility of 3D printing construction in response to current market challenges, innovation, and the 2050 net-zero carbon goal. Utilising Building Information Modelling (BIM) and Life Cycle Assessment (LCA) approaches, this study investigated the environmental impacts of three housing types: 3D printing (3DP), light steel framed (LSF), and timber. This study used cradle-to-cradle as the system boundary. The results indicate that the 3DP house emits 20% fewer carbon emissions than the traditional timber house and 25% less than the LSF house. Additionally, the 3DP house exhibits a 19% lower annual electric energy consumption than the timber house. Therefore, in response to the growing housing demand in New Zealand, the construction industry must innovate and embrace digital and advanced construction methods, including the adoption of 3D printing. Full article

The construction industry, despite its anticipated significant growth, has struggled with low productivity over the past two decades. Design for manufacturing and assembly (DfMA), a methodology with a history of success in other industries, presents a promising solution to enhancing efficiency in construction. This article reviews the current state of DfMA in the construction industry, identifies the most recent research themes in the field of DfMA, and provides recommendations for future DfMA research based on the existing research gaps. The paper employs a mixed-method approach, combining quantitative bibliometric analysis and qualitative thematic analysis. Using Scopus as the literature database, the study identified 43 relevant articles published between 2013 and 2023. The bibliometric analysis reveals a growing interest in DfMA research, with an upward trend in publications over the years. The thematic analysis categorizes DfMA research topics into six main themes: Innovation and Technology Trends, Sustainability and Environmental Impact, Regulatory and Policy Considerations, Collaborative Approach, Applications, Benefits, and Challenges, and Project Lifecycle. Each theme is explored in-depth, providing insights into the transformative impact of technology, environmental considerations in DfMA, regulatory challenges, collaborative strategies, varied applications, and the project lifecycle phases influenced by DfMA. The article concludes by presenting identified research gaps and offering recommendations for future DfMA research. It emphasizes the need for a holistic approach, continued collaboration, and a focus on unexplored aspects of regulatory frameworks and the entire project lifecycle. This study sets a new benchmark in DfMA research by employing a novel mixed-method approach and providing unprecedented insights into the multifaceted role of DfMA in advancing construction industry practices. It serves as a valuable resource for researchers, practitioners, and stakeholders in the construction industry by offering a comprehensive understanding of DfMA’s current state and guiding future research endeavors. Full article