Pushing the Envelope: Building Enclosure Commissioning (BECx) in Commercial Passive House Projects
30 September 2014
architecture | research | writing
While working as a Green Building Consultant at Baumann Consulting, I wrote this paper for publication in the proceedings of the 9th Annual North American Passive House Conference.
Published in the proceedings of the 9th Annual North American Passive House Conference (NAPHC2014) held in the Bay Area of California September 10-14, 2014.
Abstract
The expansion of the North American Passive House movement from predominantly single-family residential buildings to increasingly more commercial and multifamily projects, echoing trends in Europe, reflects exciting developments in the industry. Although LEED is still the most widely adopted green building standard for institutional and large commercial buildings worldwide, many projects looking to push the envelope of energy efficiency and high-performance are turning to stricter energy performance rating systems, with Passive House as a natural choice. Designing a larger building means greater economies of scale—proportionally smaller increases in peak loads, mechanical system sizing, and construction costs relative to increases in conditioned floor area. In simple terms, a greater emphasis on “place efficiency” drives denser development, making the “green” building more economical. Building Enclosure Commissioning (BECx) is a growing practice that can prove invaluable to architects and engineers working on projects aiming for the Passive House standard.
Consisting of a combination of processes including design review, inspections and testing of the building enclosure during and after construction, BECx came about due to the industry’s increasing emphasis on the importance of the building enclosure. From Belgium’s bold move—adopting Passive House as its national building standard in 2013—to the incorporation of BECx requirements in the Fundamental Commissioning prerequisite in the recently released LEED v4, the pivotal role of the enclosure in achieving low-energy buildings can no longer be ignored. The building enclosure is already a key component to achieving the Passive House standard through emphases on thermal bridging, airtightness, superinsulation, and other construction details to meet the energy demand and airtightness metrics of the standard. In other words, Passive House practitioners already know why the enclosure is so important—BECx is simply a formalized process of translating the complexities of Passive House construction into a navigable, straightforward process that can be communicated to the design team at large in order to produce the desired performance outcomes.