Unlocking efficiency in timber frame construction: a comparative study of on-site vs. off-site approaches in Scotland

Abstract

This study evaluates the effectiveness of on-site versus off-site timber frame construction (TFC) for low-rise housing in Scotland, specifically addressing sustainability, cost, time efficiency, and quality control to support the Scottish government’s target of delivering 110,000 affordable homes by 2032. Data were collected using a mixed-methods approach, comprising a quantitative survey of 100 construction professionals and qualitative interviews with two senior industry managers. The quantitative data were analysed using statistical methods, including frequency and mean analysis, while the qualitative data were analysed using thematic analysis. The findings reveal that off-site offers advantages in terms of time efficiency and quality control, reducing on-site labour and ensuring consistent production. However, high initial costs and logistical challenges hinder widespread adoption, particularly in remote areas. On-site TFC remains more adaptable and cost-effective in such regions, benefiting from readily available labour and material flexibility. Sustainability outcomes varied based on material usage and transportation, with off-site reducing waste but often using less eco-friendly insulation. While 80% of respondents favoured off-site for quality control, concerns about insulation settlement and moisture risks existed. Accordingly, the choice between on-site and off-site methods depends on project scale, location, and budget. Off-site is better suited for large-scale developments, while on-site methods remain practical in rural areas. This study contributes by highlighting the importance of context-specific considerations in choosing construction methods and supports the strategic alignment of TFC practices with Scotland’s housing targets.