Offsite Construction in the Australian Low-rise Residential Buildings: Application Levels and Procurement Options

Prefabricated housing has become a booming industry across the world. However, the uptake of offsite construction (OSC) approaches in Australian low-rise residential buildings is rather low compared to high-rise buildings in Australia and other countries. This study aims to investigate and analyse the adoption of different levels of OSC approaches and the selection of different procurement options in Australian low-rise residential buildings. The research objectives were pursued through the explanatory mixed research method. A comprehensive literature review is conducted using journal articles, conference papers, books, industry and technical reports and recognised websites to identify barriers of applying OSC in Australian low-rise residential buildings, different OSC approaches and different procurement options. The study identified 34 OSC barriers from the literature review under the 6 categories of (1) cost, (2) design, quality and process, (3) regulatory, (4) industry and market culture, (5) skills and knowledge, and (6) supply chain and logistics. An empirical questionnaire survey was carried out with 35 professionals in the Australian building and construction industry to investigate the occurrence and significance of the identified barriers, explore the suitability of different OSC approaches for low-rise residential construction and different procurement options for each OSC approach. The findings of questionnaire survey demonstrated 19 critical barriers to OSC uptake, 5 OSC approaches suitable for low-rise residential construction and 3 main procurement options for each OSC approach. These results were further analysed via semi-structured interviews with 20 interviewees. Semi-structured interviews were conducted to (1) carry out an in-depth discussion about the identified barriers based on the professional opinions, knowledge and experiences, (2) collect stakeholder perceptions on applying different procurement options for each OSC approach and (3) carry out an in-depth discussion on identifying suitable business models based on the identified procurement options. The findings of semi-structured interviews proposed 8 business models under the 3 previously identified procurement options. These 8 business models were further evaluated via an expert review to identify the most applicable and suitable business model for the Australian low-rise residential building industry considering the current technical, economic, social, and regulatory conditions. The findings of this study revealed that the most suitable OSC level for Australian low-rise buildings is components-based prefabrication. The study also showed that the best option of procuring prefabricated products is from Australian manufacturers, followed by Australian suppliers/dealers and overseas manufacturers. Panelised prefabrication and components-based prefabrication are ranked as the most suitable OSC approaches for Australian manufacturers. Modular prefabrication is regarded as the most suitable for the overseas manufacturer, while components-based prefabrication is the most suitable for Australian suppliers/dealers. Nevertheless, from the expert review, it was identified that local manufacturing is unrealistic due to the high cost and lack of resources; therefore, supplier/ dealer models are the most suitable procurement option. Dealer model D3 was identified as the most suitable business arrangement for Australian low-rise residential building sector. The selection of various OSC approaches and different procurement options in the low-rise residential buildings are scarcely explored topic. The outcome of this research proposes most applicable and practical way of adopting OSC methods in Australian low-rise residential construction sector.<p></p>