Quality Management in the Design and Construction of Enclosure Systems
In recent years, building scientists and technically-grounded design professionals have established that durable, high performance building enclosures must incorporate the following five control layers: a water-shedding surface, a water-resistive barrier, a thermal barrier, an air barrier and a vapor barrier. These control layers have been characterized as the five “critical barriers” of the building enclosure. Not only is it important that these five barriers – and their continuity – are provided for in the design of the enclosure, but the continuity of those barriers must be provided for with the implementation of the design during the construction phase of the project. A lack of critical barrier continuity can lead to durability problems with rot or corrosion resulting from water leakage or interstitial condensation, and/or energy performance (or comfort) problems resulting from air leakage or thermal bridging.
This paper will discuss aspects of the quality management approach utilized by one construction firm working in the Pacific Northwest to provide cost-effective, high quality, durable enclosures for high performance buildings. It will trace the process by which continuity is established during the design phase and how that continuity is achieved during the construction phase. A key point of discussion is that a vital quality approach is not based primarily on the use of outside “third party” specialist consultants or by rote use of generalized quality checklists, but on the active, collaborative engagement of knowledgeable, diligent professionals, at all points along the project process, on all sides of the table, working to get the job done – one project at a time. Other key points include:
1) the purpose of quality management is to bring order to the chaos inherent in the modern day construction delivery system
2) nearly all buildings are prototypes and this has an impact on how much standardization is possible in the development of quality processes,
3) the quality of detailing provided by the design team is of critical
importance to a successful construction process
4) the general contractor fundamentally “owns” the coordination process and must have organizational capability to understand building science and direct the construction of building enclosures utilizing that understanding.
Case studies of the quality management process from several projects will be used to illustrate the ideas and concepts discussed in the paper.