Using the Whole-Building Design Approach to Incorporate Daylighting into a Retail Space

Daylighting is the most important element in creating a low-energy building in many climates. Reducing lighting loads decreases the electrical energy required for operating lighting systems and reduces building cooling loads. However, many commercial building owners are skeptical about daylighting strategies because of the perceived risk associated with what is considered a “new” concept. Also, architects and engineers find it difficult to optimize the daylighting system so as to minimize the sum of heating, cooling, lighting, and ventilation energy costs, and to control glare. This reluctance is especially true in the retailbuilding sector where “bright” lighting is equated to meeting product sales goals. This paper described using the whole-building design approach to implement daylighting and other strategies into the BigHorn Center, a collection of home improvement retail spaces in Silverthorne, Colorado. The complex was constructed in three phases. Daylighting was an integral part of the design of the Phase Ill building. Energy consultants optimized the daylighting design through detailed modeling using an hourly building energy simulation tool Substantially reducing the electric lighting load minimized the cooling loads, which could then be completely met with natural ventilation. Other strategies included optimized envelope features, radiant slab heating, and optimized building controls. This paper focuses on the daylighting design of the Phase III building and summarizes the findings from the building envelope and systems design analyses.