Functional Performance Testing Within the Building Envelope Commissioning Process

With the growing need to construct energy efficient and durable buildings, building owners mandate a means to ensure that the building envelope is designed and constructed to meet the desired performance requirements. Commissioning the entire building envelope, from the design concept through to the completion of construction, is the most effective means to ensure that the building envelope is constructed to meet the design intent, expected service life, code requirements, and to aid in the prevention of complications that otherwise might arise during the construction process. One of the most significant, misunderstood, and often overlooked, aspects of the building envelope commissioning process is functional performance testing, and the development, integration and implementation of complete and effective functional performance testing protocols into the building envelope commissioning program.

This paper will discuss the many aspects of functional performance testing, from pre-construction laboratory materials and assembly testing, to mockup testing, through to quality control and quality assurance onsite field testing, focusing primarily on the air, water, structural and thermal performance of fenestration and cladding components used on building envelopes. This will include a discussion of the desired end results of functional performance testing, the different test methods and procedures commonly utilized both in laboratory material and system testing and field component and assembly and whole building testing, mockup testing versus field testing and the common ways that minute field alterations have significant effects on performance, and sampling procedures. The paper hopes to dispel some of the myths regarding these tests, and discuss some common misunderstandings about the test procedures and their effectiveness. The paper will conclude with a discussion on the interpretation of test results and identify some common examples of how test results can be misinterpreted.