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The construction industry is a key contributor to greenhouse gas emissions, with buildings alone accounting for 39% of the global energy-related carbon emissions. Global carbon emissions from building operations increased by 5% in 2021 compared to 2020. However, the United Nations signed the Paris Climate Agreement in 2015 with global leaders, setting a limit to temperature increases below 2.0 °C or 1.5 °C. To achieve this goal, countries have established net-zero targets to reach carbon neutrality by mid-century. However, while some countries are making significant progress, others lag behind. Therefore, this study focuses on evaluating the actions taken by countries toward carbon neutrality, and on developing a policy roadmap for the construction industry to meet the net-zero-carbon commitments. This research adopted a systematic document review, including document analysis. The evaluation of countries’ practices towards achieving net-zero targets reveals both similarities and differences. The policy maps developed can be customised for decarbonising a country’s overall construction industry and building sector. This study provides insights for research, practice, and society, emphasising the importance of achieving net-zero targets through the implementation of policies, roadmaps, plans, and strategies.

In light of climate change, the construction industry plays a crucial part in alleviating carbon emissions and other environmental impacts. The focus on improving the public procurement process poses an important opportunity for the successful implementation of carbon reduction strategies in construction projects. There is a growing body of literature mapping green and sustainable procurement practices in construction. However, previous studies have not treated the implementation of procurement in a particular area, such as carbon reduction, in much detail. This study aims to investigate the implementation of construction procurement incorporating carbon reduction strategies, with a specific focus on the public sector in New Zealand. The research was conducted through 13 semi-structured interviews with construction procurement experts in New Zealand. The results shed light on the current implementation of carbon reduction strategies in construction procurement and its challenges, such as a lack of knowledge and ambiguous procurement guidelines and documents. It also emphasises the importance of (1) well-developed carbon reduction evaluation criteria, (2) specifying a budget for carbon-related initiatives, and (3) the prerequisite of a high level of innovation in the procurement document. The study adds to the rapidly expanding field of carbon reduction construction procurement by providing a deeper insight into the way carbon reduction strategies are effectively implemented in the procurement process.

Over recent years, the British government has been investing billions of pounds in new and refurbished healthcare building projects. With the rapid growth in investment in healthcare infrastructure throughout the United Kingdom, a number of sustainability issues have been created, including construction waste generation. There is growing consensus in the literature that healthcare buildings are “complex”, due to their unique functional and operational features, and are thus more prone to generating larger amounts of construction waste. However, no significant research has been undertaken to identify the relationships between complex features in building projects and construction waste production, which is the focus of this study. Twenty-five semi-structured interviews and a questionnaire survey were conducted among healthcare clients, contractors, and architects. A life cycle approach has been adopted in this study to holistically assess and evaluate the effects of complexities with construction waste causes in healthcare projects. The findings reveal that the complex shapes and sizes of rooms, and mechanical and electrical services, significantly impact waste caused by such things as: incomplete briefing, incorrect drawing details, complex designs, non-standard designs, and inadequate communication and coordination in the pre-design, design, and construction stages.

Several studies have documented benefits of prefabrication system (prefab) compared to the traditional building system (TBS). However, the documented benefits have been anecdotal or fragmented with reports of isolated case study projects. Few studies have looked at the objectively quantified benefits from statistical significance point of view and across building types in New Zealand. This study contributes to filling this knowledge gap by analyzing cost and time-savings, and productivity improvement achievable by the use of prefab in place of the TBS. Records of completion times and final contract values of 66 building projects implemented using prefab in Auckland were collected. The building types included commercial, houses, apartments, educational, and community buildings. The project details included final contract sums, completion dates, gross floor areas, and number of floors. Based on these details, the equivalent completion times and the final cost estimates for similar buildings implemented using the TBS were obtained from the Rawlinsons construction data handbook and feedback from some designers and contractors. Marginal productivity outcome for each building project was computed as the product of the cost and time-savings achieved using the prefab. Results showed that the use of prefab in place of TBS resulted in 34% and 19% average reductions in the completion times and costs, respectively. This also translated to overall 7% average improvement in the productivity outcomes in the building projects. Univariate ANOVA-based hypothesis test results showed that ‘building type’ had no significant effects on the cost and productivity improvement outcomes, but had significant effect on the time savings analyzed in the case study projects. The greatest productivity gain of 11% was achieved in house projects. These evidence-based results could guide optimized use of prefab for specific building application. The hypothesis-testing outcome provides insights on one of several potential influences on prefab improvements, which will be analyzed in subsequent research.