Prefabricated construction has been widely accepted as an alternative to conventional cast-in-situ construction, given its improved performance. However, prefabricated concrete building projects frequently encounter significant delays. It is, therefore, crucial to identify key factors affecting schedule and explore strategies to minimise the schedule delays for prefabricated concrete building projects. This paper adopts the decision-making trial and evaluation laboratory (DEMATEL) model and analytic network process (ANP) method to quantify the cause-and-effect relationships and prioritise the key delay factors in terms of their importance in the Chinese construction industry. The DEMATEL model evaluates the extent to which each factor impacts other factors. The quantified extents are then converted into a prioritisation matrix through ANP. The delay factors of prefabricated construction projects are selected and categorised based on a literature review and an expert interview. Questionnaires are then implemented to collect the data. The results reveal that the issue of inefficient structural connections for prefabricated components is found to be the most significant factor and most easily affected by other delay factors. This research also suggests prioritising major delay factors, such as ‘lack of communication among participants’ and ‘low productivity’, in the Chinese construction industry during scheduling control. Overall, this research contributes an assessment framework for decision making in the scheduling management of prefabricated construction.
CO2 emissions from building operations have increased to their highest level, moving away from the Paris Agreement goal of below 2 °C. Zero carbon housing (ZCH) has been identified as a viable solution to realise carbon neutrality. However, ZCHs are barely recognised by the mainstream market due to the misconception of high up-front cost. This research aims to identify affordable solutions for ZCH by synergising building design, mechanical services, and renewable energy, and to balance capital cost and environmental benefits. An integrated framework of energy simulation, sensitivity analysis, and multi-objective optimisation is employed to achieve the goals. A representative house design is selected to demonstrate the proposed methodology, and a national energy rating scheme in Australia, NatHERS, is used for validation. The optimisation identified eight optimal solutions, resulting in a CO2 emission reduction between 1.894 tCO2 to 2.259 tCO2 with increased indoor comfort of 1.3%–2.6%. This research also finds that given the policy incentives, the actual incremental cost is marginal after the government rebate. This research addresses the major barriers of the high up-front cost associated with ZCH through an integrated approach. The research facilitates the paradigm shift in the mainstream market, promoting the development and market expansion of ZCH.
27 September 2021 in Engineering, Construction and Architectural Management
Purpose: This paper presents a developed spatial-temporal analysis framework for the case of investigating the business performance of construction consultancy services (CCS) in China.Design/methodology/approach: The spatial-temporal analysis is based on the data envelopment analysis (DEA) technique. The spatial analysis follows the DEA results under a contemporaneous benchmark technology and a virtual decision-making unit, consisting of ranking analysis, cluster analysis and variation analysis. The temporal analysis is reliant on the DEA results under a global benchmark technology and the time value of money, including trend analysis and driving force analysis containing pure technical and scale efficiency factors.Findings: Three CCS types in China are investigated, including engineering survey and design, construction supervision and procurement agency. The performance rank order and cluster classifications are mainly related to economic development levels. Engineering survey and design demonstrates the best performance and higher imbalances; however, construction supervision and procurement agency illustrate lower performance and imbalances. Scale efficiency significantly promotes business performance, whereas pure technical efficiency plays an inconspicuous role.Practical implications: The CCS promote technical efficiency by developing their service and innovation levels. The service of engineering survey and design registered in Beijing, Shanghai and Guangdong is recommended for entering the service market in China.Originality/value: The spatial-temporal analysis framework was developed, which is generic and provides a pathway to measure, compare and assess performance comprehensively. The CCS business performance is firstly measured.