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The purpose of this study is to evaluate the sustainability performance of modular construction from a life cycle perspective. So far, the sustainability performance of modular buildings has been explored from a life cycle viewpoint. There is no comprehensive study showing which material is the best choice for modular construction considering all three sustainable pillars. Therefore, a life cycle sustainability performance framework, including the three-pillar evaluation framework, was developed for different modular buildings. The materials are concrete, steel and timber constructed as a modular construction method.

Transitioning the built environment to a circular economy is vital to achieving sustainability goals. Modular construction is perceived as the future of the construction industry, and in combination with objective sustainability, it is still in the evaluation phase. A life cycle sustainability assessment, which includes life cycle assessment, life cycle cost and social life cycle assessment, has been selected to evaluate alternative materials for constructing a case study building using modular strategies. Subsequently, the multi-criteria decision-making (MCDM) method was used to compute the outranking scores for each modular component.

The calculated embodied impacts and global warming potential (GWP) showed that material production is the most critical phase (65%–88% of embodied energy and 64%–86% of GWP). The result of embodied energy and GWP shows timber as an ideal choice. Timber modular has a 21% and 11% lower GWP than concrete and steel, respectively. The timber structure also has 19% and 13% lower embodied energy than concrete and steel. However, the result of the economic analysis revealed that concrete is the most economical choice. The cost calculations indicate that concrete exhibits a lower total cost by 4% compared to timber and 11% higher than steel structures. However, the social assessment suggests that steel emerges as the optimal material when contrasted with timber and concrete. Consequently, determining the best single material for constructing modular buildings becomes challenging. To address this, the MCDM technique is used to identify the optimal choice. Through MCDM analysis, steel demonstrates the best overall performance.

This research is valuable for construction professionals as it gives a deliberate framework for modular buildings’ life cycle sustainability performance and assists with sustainable construction materials.

Modular construction is an innovative method that enhances the performance of building construction projects. However, the performance of steel modular construction has not been systematically understood, and the existing measurement methods exhibit limitations in effectively addressing the features of steel modular building construction. Therefore, this study aims to develop a new performance measurement framework for systematically examining the performance of steel modular construction in building projects.

This study was conducted through a mixed-method research design that combines a comprehensive review of the state-of-the-art practices of construction performance measurement and a case study with a 17-story steel modular apartment building project in Hong Kong. The case project was measured with data collected from the project teams and other reliable channels, and the measurement practices and findings were referenced to establish a systematic performance measurement framework for steel modular construction.

Considering steel modular construction as a complex socio-technical system, a systematic performance measurement framework was developed, which considers the features of steel modular construction, focuses on the construction stage, incorporates the views of various stakeholders, integrates generic and specific key performance indicators and provides a benchmarking process. Multifaceted benefits of adopting steel modular construction were demonstrated with case study, including improved economic efficiency (e.g. nearly 10% cost savings), improved environmental friendliness (e.g. approximately 90% waste reduction) and enhanced social welfare (e.g. over 60% delivery trips reduction).

This paper extends the existing performance measurement methods with a new framework proposed and offers experience for future steel modular construction. The measured performance of the case project also contributes in-depth understanding on steel modular construction with benefits demonstrated. The study is expected to accelerate an effective uptake of steel modular construction in building projects.

Modular construction is considered a well-established construction method for improving the efficiency of the construction industry worldwide. However, the industry struggles to achieve higher levels of modularisation in urban areas. Previous studies on decision-making for modularisation have, so far, not focussed much on its application in urban areas. As modular construction could bring lots of advantages such as speed of construction, This study aims to develop a decision-making tool that can assist the project planners in deciding whether the modular construction techniques should be applied in their urban area project.

Based on the literature review, a total of 35 decision-making factors of modularisation were identified for this study. The decision-making model is then developed to evaluate the significance of each factor using the analytic hierarchy process (AHP) approach. A total number of 72 valid responses were obtained and analysed. The geometric mean of priorities is adopted to obtain the par-wise comparison between the critical factors in which each factor’s weighting in the decision-making model is calculated. Afterwards, the robustness of the decision-making model is demonstrated by the real-life projects in China, Hong Kong and the UK, respectively.

A total of 35 decision-making factors allocated in five criteria for modular construction selection in urban areas were identified. The criteria include site attributes, project characteristics, labour consideration, environmental and organisation and project risk. Their impact was calculated using the AHP to indicate the relative importance with respect to the adoption of modularisation in urban areas. Afterwards, a two-level decision-making model was developed that can be used as a decision-making tool for the adoption of modular construction.

The outcome of this research will be beneficial to industrial practitioners and academics in understanding the critical attributes that affect the adoption of modular construction in an urban area. It further enables the building professionals to assess the feasibility of using modular construction in their projects, especially at the early stage, so as to facilitate its use.

There is a number of literature on the decision-making model on the adoption of modular construction. However, previous studies did not provide specific concerns related to urban areas, whereas there is an urgent need to have an updated analysis that can be catered to the modular construction in the urban area. In this research study, the 35 decision-making factors were ranked by the experienced project managers and then a pair-wise comparison was conducted. With this information, the robust decision-making model is formulated to offer a kept promised indicator in adopting modularisation in the urban area.

The practice of artificial intelligence (AI) is increasingly being promoted by technology developers. However, its adoption rate is still reported as low in the construction industry due to a lack of expertise and the limited reliable applications for AI technology. Hence, this paper aims to present the detailed outcome of experimentations evaluating the applicability and the performance of AI object detection algorithms for construction modular object detection.

This paper provides a thorough evaluation of two deep learning algorithms for object detection, including the faster region-based convolutional neural network (faster RCNN) and single shot multi-box detector (SSD). Two types of metrics are also presented; first, the average recall and mean average precision by image pixels; second, the recall and precision by counting. To conduct the experiments using the selected algorithms, four infrastructure and building construction sites are chosen to collect the required data, including a total of 990 images of three different but common modular objects, including modular panels, safety barricades and site fences.

The results of the comprehensive evaluation of the algorithms show that the performance of faster RCNN and SSD depends on the context that detection occurs. Indeed, surrounding objects and the backgrounds of the objects affect the level of accuracy obtained from the AI analysis and may particularly effect precision and recall. The analysis of loss lines shows that the loss lines for selected objects depend on both their geometry and the image background. The results on selected objects show that faster RCNN offers higher accuracy than SSD for detection of selected objects.

The results show that modular object detection is crucial in construction for the achievement of the required information for project quality and safety objectives. The detection process can significantly improve monitoring object installation progress in an accurate and machine-based manner avoiding human errors. The results of this paper are limited to three construction sites, but future investigations can cover more tasks or objects from different construction sites in a fully automated manner.

This paper’s originality lies in offering new AI applications in modular construction, using a large first-hand data set collected from three construction sites. Furthermore, the paper presents the scientific evaluation results of implementing recent object detection algorithms across a set of extended metrics using the original training and validation data sets to improve the generalisability of the experimentation. This paper also provides the practitioners and scholars with a workflow on AI applications in the modular context and the first-hand referencing data.

The construction industry in developed countries is witnessing a paradigm shift towards modular construction methods, driven by the need for efficiency, sustainability, and cost-effectiveness. However, the realization of these benefits in the context of developing countries is hindered by numerous barriers. Against this backdrop, this study seeks to contribute insights into the barriers hindering the adoption of modular construction in developing countries, specifically Nigeria, and further formulate effective strategies.

A thorough review of existing literature was conducted to identify the multifaceted barriers hindering the adoption of modular construction and the corresponding strategies. Subsequently, a panel of 13 experts were invited to utilize the Fuzzy Analytic Hierarchy Process (FAHP) approach to systematically evaluate these barriers based on their impact. Furthermore, the experts implored the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) approach to select and prioritize the most suitable strategies to mitigate these barriers.

The study revealed that the most critical barriers to modular construction are Client resistance to change and innovation, Limited experience in module installation, and Transportation constraints. Additionally, the study prioritizes 13 strategies, with the Development of effective guidelines, standards, and policies ranked highest. The insights from the ranking using the FAHP and TOPSIS approach were adopted to develop a framework for modular implementation in developing countries.

This study is limited to Nigeria due to its status as the country with the highest Gross Domestic Product (GDP) in Africa, and it is considered a suitable representation of the region as most of the countries in Africa are categorized as developing nations.

By highlighting the most critical barriers and prioritizing effective strategies, the study provides actionable insights for overcoming obstacles to modular construction adoption. Decision-makers can use this information to develop targeted policies and training programs to promote the adoption of modular construction in developing countries.

The research provides valuable insights by not only identifying critical barriers but also presenting prioritized strategies, distinguishing itself from previous studies, and establishing itself as a novel resource for developing countries. This adopt a novel hybrid MCDM approach for modular construction in developing countries such as Nigeria which can serve as reference point to other developing countries seeking to adopt modular construction and leverage its numerous benefits.

With many natural disasters such as earthquakes, cyclones, bushfires and tsunamis destroying human habitats around the world, post-disaster housing reconstruction has become a critical topic. The current practice of post-disaster reconstruction consists of various approaches that carry affected homeowners from temporary shelters to permanent housing. While temporary shelters may be provided within a matter of days as immediate disaster relief, permanent housing can take years to complete. However, time is critical, as affected communities will need to restore their livelihoods as soon as possible. Prefabricated modular construction has the potential to drastically improve the time taken to provide permanent housing. Due to this time-efficiency, which is an inherent characteristic of modular construction, it can be a desirable strategy for post-disaster housing reconstruction. This paper discusses how prefabricated modular structures can provide a more time-efficient solution by analysing several present-day examples taken from published post-disaster housing reconstruction processes that have been carried out in different parts of the world. It also evaluates how other features of modular construction, such as ease of decommissioning and reusability, can add value to post-disaster reconstruction processes and organisations that contribute to the planning, design and construction stages of the reconstruction process. The suitability of modular construction will also be discussed in the context of the guidelines and best practice guides for post-disaster housing reconstruction published by international organisations. Through this analysis and discussion, it is concluded that prefabricated modular structures are a highly desirable time-efficient solution to post-disaster housing reconstruction.

This paper describes the development and implementation of a modular school building design prototype to support “build back better” after the disaster. The purpose of this paper is to bridge the gap between the two standard practices of post-disaster reconstruction: the quickly temporary construction and the permanent solution with longer time to complete.

The modular school design prototype was developed based on three design criteria established to achieve a relatively quick construction with good quality as a post-disaster permanent solution. The prototype was implemented in Kerandangan Village, Lombok and evaluated to review its compliance with the design criteria.

Three design strategies were proposed to respond to the main design criteria: the use of modular units and components, the material durability and availability, and the “plug-and-play” configuration system. Through these strategies, the prototype demonstrated the ability to perform as a permanent solution to be implemented in a short time. The prototype evaluation suggests some possible improvement to ensure a more efficient process and further replicability.

The development of the modular design bridges the gap between temporary and permanent approach for post-disaster school reconstruction. The highlighted criteria and the proposed design strategies contribute to the “build back better” attempt by providing better learning experiences for children through a replicable modular design that could be flexibly adapted to various local contexts.

Housing completions in the UK have fallen to 125,000 annually, while government targets have risen to 300,000. This dramatic shortfall raises concerns as to whether current traditional construction approaches remain appropriate. This study aims to compare the traditional approach with modular construction, with a view to assessing whether a shift in construction systems offers the potential to alleviate the UK's domestic housing crisis.

A comprehensive interpretivist review of the available relevant literature is undertaken on construction methods within the UK; advantages and disadvantages. A bibliometric analysis is conducted to extract trends and findings relevant to the comparison at hand. The database is Web of Science; the analysis software is the VOS viewer.

The research illustrates that the UK housing market is in a state of crisis. A toxic combination of a rising UK population combined falling rates of housing delivery has resulted in an ever-widening housing supply gap. The construction industry’s capacity to meet this observed dearth in supply is further exacerbated by a number of chronic factors such as: falling participation in the construction sector workforce; lowering skill levels; reducing profitability; time to delivery pressures; and cost blow-outs.

While much information on the various construction methods are available, including comparative material, this study is the first to assemble the various comparative parameters regarding traditional and modular UK residential construction in one place. Thus, this study provides a definitive assessment of the relative advantages and disadvantages of these forms of construction.

Modular construction is widely used for residential buildings of 4 to 8 storeys. In the context of open building systems, modular construction provides a systemised approach to design in which the benefits of prefabrication are maximised. There is demand to extend this form of construction to more than 12 storeys for residential buildings. This paper presents a review of modular technologies, and describes load tests and analysis on light steel modular walls that are used to justify the use of light steel technology to support higher loads.

For taller modular buildings, the effect of installation and geometric inaccuracies must be taken into account and it is proposed that maximum out of verticality of a vertical group of modules is 50mm relative to ground datum. Using these geometric tolerances, the notional horizontal force used to evaluate stability of a group of modules should be taken as a minimum of 1% of the applied vertical load on the modules. Robustness to accidental load effects is important in all high-rise buildings and it is proposed that the tie force in the connections between modules should be taken as not less than 30% of the total vertical load applied to the module in both horizontal directions.

This study aims to identify the primary research areas of modern methods of construction (MMC) along with its current trends and developments.

A combination of bibliometric and qualitative analysis is adopted to examine 1,957 MMC articles in the Scopus database. With the support of CiteSpace 6.1.R6, the clusters, leading authors, journals, institutions and countries in the field of MMC are examined.

Offsite construction, inter-modular connections, augmenting output, prefabricated concrete beams and earthquake-resilient prefabricated beam–column steel joints are the top five research areas in MMC. Among them, offsite construction and inter-modular connections are significantly focused, with many research articles. The potential for collaboration, among prominent authors such as Wang, J., Liu, Y. and Wang, Y., explains the recent rapid growth of the MMC field of research. With a total of 225 articles, Engineering Structures is the journal that has published the most articles on MMC. China is the leading country in this field, and the Ministry of Education China is the top institution in MMC.

The findings of this study bear significant implications for stakeholders in academia and industry alike. In academia, these insights allow researchers to identify research gaps and foster collaboration, steering efforts toward innovative and impactful outcomes. For industries using MMC practices, the clarity provided on MMC techniques facilitates the efficient adoption of best practices, thereby promoting collaboration, innovation and global problem-solving within the construction field.