Investigating the cost of offsite construction housing in Western Australia

Abstract

Purpose Offsite construction approaches and methodologies have been proffered a potential solution for controlling “traditional” projects, especially where high levels of complexity and uncertainty exist. Given this, locations such as Western Australia (WA), where there are unique housing provision challenges, offsite construction method was considered a potential solution for not only addressing the complexity/uncertainty challenges but also alleviating the housing shortage. However, whilst acknowledging the benefits of offsite construction, recognition was also noted on perceived barriers to its implementation, primarily relating to cost uncertainty. This recognition is exacerbated by very limited offsite construction cost data and information available in the public domain. In response to this, this paper sims to provide detailed cost analysis of three offsite construction projects in WA. Design/methodology/approach To hold parameters constant and facilitate cross-case comparative analysis, data were collected from three embedded case studies from three residential housing projects in WA. These projects represent the most contemporary implementation of offsite in WA; where two were completed in 2016/2017 and the third project was still ongoing during the data collection of this research. The research methodological approach and accompanying data analysis component engaged a variety of techniques, which was supported by archival study of project data and evidence gathered from the offsite construction provider. Findings Core findings revealed three emerging themes from residential offsite construction projects pertinent to cost. Specifically, the overall cost of delivering residential housing project with offsite construction techniques, the cost variability of offsite construction residential housing projects as impacted by uncertainties and the cash flow of residential offsite construction projects based on the payment term. These three major cost drivers are elucidated in this paper. Originality/value This research presents new cost insights to complement the wider adoption of offsite construction techniques. It presents additional information to address the limited cost data and information of offsite construction projects available in the public domain particularly for residential housing projects (within the bounded context of WA). It also highlights the further stages needed to enhance data validity, cognisant of universal generalisability and repeatability, market maturity and stakeholder supply chains.

Patterns and trends in Internet of Things (IoT) research: future applications in the construction industry

“…It is with a view to address these issues through innovation that researchers have endeavoured to use product technologies and process improvements to augment competitiveness in the construction industry (Fewings and Henjewele, 2019). However, since material costs typically dominate construction projects (Sutrisna et al, 2019), there is an inclination to prioritise "product" over "process" innovations. Under the "product" innovation umbrella, numerous techniques associated with Industry 4.0 have been used to provide innovative solutions to solve construction problems (Bu et al, 2015).…”

Assembly Process in Off-Site Construction: Self-Lock Device as a Key to a Lean Approach

“…Hence, assembly process is estimated to be four times quicker with the use of ACDs, leading, again, to major cost reduction. Sutrisna et al (2019) presented the findings of their work on the off-site manufacturing cost analysis based on three study cases in Australia. To compare with this research, all cost components values were divided by the number of modules involved in each study case, mean values were computed, converted to CAD$ and are presented in Table 4.…”

“…To compare with the results of this paper, the impact of an ACD is evaluated by computing the hypothetical total cost/module if off-site completion was maximized to 90%. The findings of Sutrisna et al (2019) state that for the study-case under consideration, on-site construction cost represented 20% of the total cost and allowed for 28% of the module completion. By interpolation, if on-site completion was reduced from 28% to 10%, the cost would reduce from $12.7K to $4.6K.…”

Development of an Offsite Construction Typology: A Delphi Study

“…Many other literature sources provide various bases for levels of OSC classification, viz. the value of the work [39], the nature of the work [40], the material used [15], the level of pre-design [41], the value addition before onsite installation [42], and the location of the work [43]. Nevertheless, a determining factor for categorizing OSC products is the product complexity [34] and the value percentage of the product out of the total project value [44].…”