ECO-STRUCTURE recently interviewed Jason Hudspeth, project architect for Empowerhouse, a joint entry from Parsons the New School for Design, the Milano School, and the Stevens Institute of Technology for the U.S. Department of Energy’s 2011 Solar Decathlon:
How is your solar paneling unique?
We embraced passive-house design principles early in the project, and this set the stage for many of our performative decisions. Through the careful placement of triple-pane windows, an airtight and super-insulated envelope, and a compact volume, we were able to minimize the size of the costly solar panel array—now verified as the smallest photovoltaic array in the competition.
What other sustainable features have you incorporated into your design?
In addition to utilizing passive-house principles, we've spent a great deal of time in systems research. The active mechanical components work synergistically to recover energy from processes that include, for example, running the clothes dryer. A loft brings light deep into the center of the home in concert with windows along the south, west, and north façades of the lower level, providing even daylight throughout the home. These features minimize the need for artificial lighting, and help reduce operational costs for the homeowner. The house is also equipped with a rain-management system that collects and filters stormwater from the roof for use in irrigation and other nonpotable uses. This system minimizes the amount of potable city water used for irrigation while also reducing the water drained into the public sewer system.
What was the inspiration of your design, and does it display any regional influences?
Our design emerged over the course of two years during which we worked closely with the Washington, D.C. chapter of Habitat for Humanity to create a new model for sustainable housing. We defined our project not only by the constraints of the Solar Decathlon, but also by the constraints set by a real site in the historic D.C. community of Deanwood. The neighborhood has evolved to include a diverse range of approaches to residential design, and we viewed our addition as the next step in that process. The design is contemporary—but this is not to say it’s foreign to the context. The scale and proportion of the neighboring houses running both east and west of our narrow lot helped set reasonable parameters for the massing of our project. Additionally, the composition of the windows and doors on the street façade reference many of the surrounding two-story homes. In keeping with the desires of the community to emphasize the importance of interaction and openness, the front porch emerged as one of the most prominent features in our design. It is a space for communal gathering, family interaction, and also a conceptual extension of our thickened building envelope.
How has the new affordability criteria affected the design of your house?
The new affordability criteria affected all aspects of our house design. Our partnership with Habitat for Humanity forced us to treat the new contest with utmost respect. We projected that the initial costs of bringing passive-house strategies to Habitat for Humanity’s existing building model would incur additional costs, and so we were keen on making the most cost-effective material choices throughout the process. We were awarded first place in the affordability contest. This was, in many ways, the most important victory for our team, and we are thrilled to have demonstrated that a highly efficient solar-powered home can be built affordably.
What will happen to the house after the Solar Decathlon?
The house is being donated to the Washington, D.C. chapter of Habitat for Humanity immediately following the competition. It will be moved to its site on Gault Place in Deanwood, where it will undergo an expansion that will include the addition of two bedrooms to the second floor. The solar panels will move to the top of the second-story addition, thereby freeing the south portion of the accessible rooftop for a garden. A mirror version of the Empowerhouse will be built to create a duplex unit for two Habitat for Humanity families. The joining of the two homes along the east wall will enable them to perform more efficiently. Once complete, the homes will be the first site net-zero residences built in Washington, D.C.