General contractors’ experience using off-site structural framing systems

Abstract

Purpose This paper aims to examine general contractors’ experiences of using off-site manufactured structural framing systems. This engaged a single-case study using a qualitative methodology to identify expected benefits, actual benefits and challenges of such systems. Design/methodology/approach A single-case study approach evaluated general contractors’ experience of using a manufactured structural framing system. Qualitative data were collated and analyzed from industry domain experts to determine commonalities and thematic thinking. Findings The study revealed that the reasons behind considering off-site building systems were: accelerating the project schedule, overcoming site constraints and having a better end-product. The top expected benefits were: saving time (schedule), saving cost and improving quality. The top actual observed benefits were: saving erection time, reducing waste generation, reducing project costs, reducing safety risks and improving construction site logistics. The main challenges encountered were: unfamiliarity of different project parties with the off-site framing system, difficulty with reducing the overall project schedule, heavy site logistics and complicated off-site system design and standards requirements. The findings include solutions to overcome the challenges associated with using a manufactured structural system. Research limitations/implications This paper was a case study and therefore inherently limited in its generalizability. The study was conducted with general contractors in the mountain-west region of the USA. However, the implications of the study may have a broad application, as contractors across the globe seek to find similar solutions to using off-site or manufactured construction methods. Practical implications Construction labor shortages around the world are forcing the construction industry to find creative solutions to meet the demand for their services. Manufactured or off-site construction methods provide a possible solution to that labor shortage. However, builders need to be aware of the immediate challenges and actual benefits of using a manufactured structural framing system. Social implications Manufactured structural framing systems have the potential to impact lean and sustainable practices in construction. Reduced waste, reduced on-site man-power requirements, reduced construction schedules and reduced injuries each improve the lives of construction workers and the communities around these buildings. Originality/value An extensive literature review was performed to guide the design of this case study. Much has been written about off-site construction practices, but there is a significant research gap on the topic of structural framing systems. This study contributes to expanding the knowledge of off-site construction and specifically helps researchers and practitioners understand the challenges and benefits of this systematic approach to construction.

Systematic review on the identification of safety risks in off-site manufacturing (OSM)

“…Close coordination between stakeholders is crucial to reduce issues pertaining to the OSM process (Heng et al , 2011). Previous research has highlighted collaboration uncertainties such as designers’ lack of awareness on safety requirements (Kim et al , 2011) and site logistics constraints due to poor communication (Killingsworth et al , 2020). Hwang et al (2018) found that OSM requires extensive collaboration prior to and during the project and suggested to use building information modelling to improve collaboration and communication among stakeholders.…”

“…For example, Heng et al (2011) utilises virtual prototyping technology with the aid of IKEA model towards the safety of prefabricated construction work. Application of robotics or machinery for unloading prefabricated component during on-site proceedings were suggested to improve safety specially when on-site installations are affected by adverse weather conditions (Killingsworth et al , 2020). With the development of information technology, emerging technologies can be synchronised with various safety management aspects such as for improving the work site, crane operations and managing the workforce (Yingbo et al , 2019; Lu and Zhu, 2021).…”

“…Contrary to traditional construction, simultaneous and parallel lift operations are undertaken at the site during the installation process, which can cause a disturbing workspace leading towards safety risks such as collision accidents and working under heavy loads (Ma et al , 2020). Although the impacts from weather conditions are expected to reduce by using OSM, still there can be instances of safety risks during unloading heavy and large prefabricated components in adverse weather conditions such as during windy situations (Killingsworth et al , 2020). Thus, this unique construction method delivers an uncertain working environment in terms of safety (Liu et al , 2018).…”

Process evaluation of construction methods to quantify safety

“…When it comes to safety research in off-site construction, topics explored include an analysis of risks in off-site versus hypothetical on-site construction scenarios for the same building components (Ahn et al, 2020); off-site construction facilities to determine root causes of safety incidents (Fard et al, 2017); and behaviours in off-site environments to predict safety outcomes (Liu et al, 2019). Additionally, much of the research surrounding safety risk assessments in offsite construction is qualitative and summarizes findings from expert opinions (Killingsworth et al, 2020) about the perceived benefits of the off-site approach.…”

Synchronising Off-Site Fabrication with On-Site Production in Construction

“…Realisation of this lean ideal will bring construction closer to series production (i.e., manufacturing). Pan and Sidwell (2011) Tam, et al (2015) Killingsworth, Mehany and Ladhari (2021 As use of OSF continues to grow, it becomes increasingly important to create a smooth flow from raw materials arriving in the factory to the installation of the resulting sub-assemblies on-site. Predictable, Just-in-time ( JIT) production in a factory is possibly easier than it is on-site, yet it is far from simple.…”