Tolerance management in prefabrication of mechanical, electrical, and plumbing installations

Prefabrication in construction has advanced. However, mechanical, electrical, and plumbing (MEP) works still lag structural and interior applications. Inaccuracies in design and installation can undermine the benefits of prefabrication, emphasizing dimensional accuracy. However, literature lacks comprehensive methods for managing tolerances in MEP prefabrication. This research aims to advance tolerance management in MEP prefabrication by formulating prescriptive principles based on best practices. A multiple case study approach with five projects was adopted. Four advanced cases and one with tolerance issues were studied. These included two hospitals, two apartment buildings, and one laboratory, representing differing functional requirements and tolerance environments. Thematic analysis was applied to interviews, documents, and site visits. Seven prescriptive principles for tolerance management in MEP prefabrication are the primary contribution. Among these, the role of communication, detailed design, and quality control are emphasized, while buffer assembly is identified as a distinctive MEP tolerance management method. The novelty and industry impact of the principles are underscored by the limited prior research and by the fact that none of the case projects applied all the principles. Adoption of these principles is recommended to guide design, manufacturing, and installation to improve productivity, reduce lead times, and enhance quality.