A fully integrated design process creates a seamless application of electric and daylighting solutions.
» Collaboration between students, practitioners, and industry is rare; but, as evidenced in Virginia Tech's house for the Solar Decathlon Competition last fall, the potential for innovation when these partners come together is high. With this project, Virginia Tech committed to breaking down some of the traditional barriers between the classroom and the real world. For the team, innovation meant the synthesis of extensive research into a unified whole that could be implemented successfully toward a specific goal, but with the potential for more widespread purpose.
Held for the second time in 2005, the biennial Solar Decathlon competition is sponsored by the United States Department of Energy (DOE) with the goal of creating and further developing sustainable energy strategies for residential construction. The interdisciplinary nature of the competition supported such a goal, allowing students from design and engineering disciplines to work together to fulfill the quantitative and qualitative criteria outlined by the competition. Eighteen international student teams installed their entries on the Mall in Washington, where they were judged in 10 categories, ranging from architectural merit to power generation ('Solar Decathlon,' Nov/Dec 2005). The Virginia Tech team members took the competition's mandate as a challenge to integrate sustainable strategies seamlessly into their competition entry, and in the process, created unconventional solutions with direct applicability. In doing so, their home won the Architecture, Dwelling, and qualitative Lighting contests, and was noted for its 'clean and integrated' design solution.
The theme for the Virginia Tech entry was 'No Compromise: the Integration of Technology and Aesthetics.' According to Joe Wheeler, assistant professor of architecture, who served as the lead project advisor, 'Every decision involving quantitative criteria was measured in terms of its contribution to spatial quality.' This played out most directly in the form of the house's roof, which is imbued with multiple functions. The V-shaped profile correctly orients solar panels, and functions as a light diffuser and a rainwater collector, while creating a lofted spatial experience inside. The roof is literally an inversion of the traditional residential roof profile, a move that carries symbolic weight as much as it offers inherent functionality.
The initial design for Virginia Tech's entry was the result of a school-wide competition intended to gain interest in the project. This 'internal' competition established the unique roof shape and helped assemble a team of nearly 80 students spanning seven disciplines (architecture, industrial design, interior design, landscape architecture, building construction, and electrical, mechanical, and structural engineering). A materials research class, taught by Wheeler and specific to the competition, provided much of the raw material for the project and established initial contacts with more than 75 different industry members. The involvement of manufacturers meant that students were able to experiment with the latest technologies, and allowed the teams to create projects that far exceeded the $5,000 stipend provided by the DOE.
Designed with a full integration of lighting solutions, architecture serves as the link between daylighting and electric lighting, allowing each formal element to serve double duty. Lighting designer Andrea Hartranft, a senior associate at Philadelphia-based C.M. Kling and Associates and a colleague of Wheeler's, served in an advisory capacity on the project, helping the team to refine its electric lighting scheme, particularly techniques for uniformly uplighting the angular ceiling. During the day, light enters the house in two modes: directly through south, east, and west clerestory windows, where it then bounces off a fabric ceiling bathing the main room with light; and through translucent wall panels, which create an interior glow. These polycarbonate panels, filled with aerogel, a clear insulating material, provide significant thermal ratings relative to the amount of light transmitted. The entire wall assembly has a resistive value of R-22 and above, with the typical residential wall ranging from R-12 to R-24.
At night, interior electric lighting takes the place of the sun's rays. A strip of T5 dimmable fluorescent fixtures, located on a light shelf just below the clerestories, illuminates the fabric ceiling to provide an ambient lighting condition, and is also supplemented with low-voltage tasklighting. On the exterior of the light shelf, an additional fluorescent fixture highlights the outer edge of the roof, defining its unique form at night. LED arrays, located at the base of the walls in the air gap between the two layers of polycarbonate sheeting, illuminate the walls from within, providing an evening glow that adds to the interior ambient light. In addition, software driving the LED arrays allows users to control the wall and change its colors on demand, making for an interesting visual for viewers both inside and out.
While the color-changing aspect of the wall is not 'necessary' it is playful, and therefore, memorable. As a result, the unique wall assembly has been used since the competition, most notably in a meditation pavilion built as part of the ABC show 'Extreme Makeover: Home Edition,' which attracted an estimated 25 million viewers. According to Wheeler, calls about the wall system have been so frequent, that they are considering manufacturing and selling it.
Gary Steffy, a Michigan-based lighting designer who served as one of the judges for the lighting contest, was impressed by the integration of architecture and lighting. 'It was a seamless application that could only have been achieved by working with the architecture from day one.' zachary r. heineman
project Virginia Tech Solar Decathlon House, Washington
design team Multidisciplinary student team at Virginia Tech, Blacksburg, Virginia
faculty advisor Joe Wheeler
images Courtesy of Virginia Tech project size Overall footprint: 800 square feet; floor plan: 590 square feet
project cost $275,000 (in-kind donations of materials and equipment); $100,000 (financial contributions)
lighting cost $25,000 (in-kind donations of materials and equipment)