Performance validation case study: Federal office building with an integrated facade

Abstract

The General Services Administration Edith Green Wendell Wyatt building has undergone an extensive retrofit and is distinguished by its new integrated facade.1 It has been transformed from a poorly performing office building into a highly efficient Leadership in Energy and Environmental Design (LEED) Platinum facility. The unitized curtain wall includes fixed exterior shading tuned for each solar orientation. The new interior environment optimizes daylight and electric lighting, thermal comfort, and air quality. This article reports on post-occupancy evaluations to validate and fine-tune the performance of Edith Green Wendell Wyatt building. The focus is on post-occupancy evaluation studies that relate to the integrated facades. Overall, post-occupancy evaluations address three categories: (1) resource use and generation—energy and water, (2) occupant satisfaction, and (3) indoor environmental quality measurements. During design, the impact of building enclosure measures and internal loads was linked directly to the selection of the mechanical system. The team determined that strategic use of glazing and exterior shading would support highly efficient hydronic radiant heating and cooling. Post-occupancy evaluation methods include installed data sources (from the building management system and other installed measurement and verification systems) and proposed field testing. Occupant satisfaction has been evaluated with an on-line survey from the Center for the Built Environment. The results have been filtered by solar orientation, floor, and other criteria to understand the facades’ impact on occupant satisfaction. Pre-occupancy results and additional benchmarking compare the results with government and other general office buildings. As of January 2015, many of the post-occupancy evaluation studies have been completed, but some are still on-going. Post-occupancy evaluation objectives include: demonstrating federal energy compliance, refining building performance, and providing feedback for future work.