Project impacts of specialty mechanical contractor design involvement in the health care industry: Comparative case study

Recent research efforts on project delivery have been heavily focused on using project-level indicators to predict cost and schedule outcomes. However, specialty contractors performing at the system level have an increasingly important role in the design and construction of healthcare and other high-performance facilities. From curtain wall assemblies to HVAC systems, specialty contractors possess the system knowledge and field expertise to support delivery of energy-efficient, cost-effective systems. Therefore, this research adapted the use of existing metrics from broader, project-level applications to a narrower building system, focused to contextualize the importance of system delivery. A comparative case study analysis was conducted to collect quantitative data on schedule and cost outcomes, construction safety, and building energy performance on two large healthcare facilities. By comparing a design-build and design-assist case, this paper demonstrates how increasing design involvement of mechanical contractors provides opportunities to reduce cost growth, schedule growth, and safety incidents, and improve the HVAC system performance in healthcare projects. Contextual lessons from the design-build case are discussed and suggested for application in other forms of project delivery.