MEASURING THE IMPACT OF MECHANICAL CONTRACTOR DESIGN INVOLVEMENT ON BUILDING SYSTEM AND PROJECT-LEVEL OUTCOMES: A COMPARATIVE CASE STUDY

Open Access
Author:
Franz, Bryan
Graduate Program:
Architectural Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
May 27, 2011
Committee Members:
  • David R Riley Ii, Thesis Advisor
Keywords:
  • Project Delivery
  • Healthcare
  • Integrated Design
  • Metrics
  • Specialty Contractors
Abstract:
Due to rising energy costs and increasing attention to indoor environmental quality, the application of sustainable or “green” practices in healthcare facilities is gaining momentum. HVAC and mechanical systems are a vital component of all healthcare facilities, accounting for nearly 45% of the building’s energy usage. In response, many healthcare owners are turning to design-build contracts, which empower a single contractor with the responsibility of designing, installing and commissioning a functioning mechanical system. Efforts to understand the impacts of integrated forms of delivery on project success have led to the development of high-performance metrics heavily focused on using project-level metrics and indicators to predict outcomes; however, specialty contractors at the building system-level have an increasingly important role in the design of sustainable buildings. To begin understanding how the early involvement of specialty contractors relates to project success and the performance of building systems, this research develops a comparison method to evaluate the contributions of the mechanical contractor during design and construction. Relationships are traced with a comparative case study of two similar hospital facilities, using existing project-level performance metrics, to identify the relationships between integrated mechanical system delivery and project outcomes. By combining detailed data obtained from primary source documents, including RFIs, change order logs, schedules and field observation, with secondary source semi-structured team interviews, this research uses explanation-building techniques to identify causal relationships. Results indicate improved cost and schedule predictability at both the project and mechanical building system-level on an integrated design-build delivery. Additionally, under a design-build arrangement, the mechanical contractor has the opportunity and incentive to engage in iterative system design, which improves the energy efficiency of the facility and reduces the likelihood of construction safety accidents.