Our House
Carnegie Mellon plugs into many different disciplines for its Solar Decathlon house

by Zach Mortice
Assistant Editor

How do you . . . put together an interdisciplinary team to design and build a solar-powered house that significantly relies on passive solar design?

Summary: Carnegie Mellon’s house for this fall’s national Solar Decathlon competition uses a core and pod structure to make it modular across different scales. It was designed by a team from many different schools of design and the arts, and contains passive as well as active solar features.

To the architecture students designing it, the Carnegie Mellon Solar Decathlon house could be called “unprogrammed space.” For the art students working on it, it could be a “blank slate,” or “unmolded clay.” All members of Carnegie Mellon’s multidisciplinary team can agree that their Solar Decathlon house is versatile and adaptable on many levels, and that this diverse team helps make it so.

“The way that we’ve been taught architecture is very much conceptual, so most of the decisions we make are based on an overriding concept,” says Emma Davison, a Carnegie Mellon architecture student. She’s the point of contact for all the different schools of study working on the house. “[In] some of the other schools, the artists have a completely different take on things. They’re an aesthetically driven field. Art’s not necessarily built with the human form in mind.”

The third Solar Decathlon will see 20 colleges design, build, and operate a solar-powered house. The National Mall in Washington, D.C., will be the site of the final competition, as students from each team live in the houses and are tasked with performing basic domestic duties there, like doing laundry, cooking, and saving enough energy to power an electric car, all from solar energy. Visitors to the Mall will be able to view the houses from October 12-20, with the winner announced October 20.

Different scales
The most important programmatic intent of the house is “trying to make the modularity of the house work on different scales,” says Davison. The smallest scale of modularity the house features is its customizable exterior and interior panels. Inside, cabinet spaces can be altered on the fly, and outside different materials can be attached to wall framing. When the house is finished, individual rooms will be covered in Queen Anne, Federal, and Georgian exteriors.

The most obvious scale of modularity of the house is what the students and their professor call “plug and play.” Carnegie Mellon Architecture Professor Steve Lee, AIA, teaches students about Louis Kahn’s famous delineations between servant spaces (utilitarian spaces whose goal is to support living spaces) and served spaces (the social spaces supplied by servant spaces), and along these lines, he and his students developed the idea of a utilitarian core and detachable pod-like living spaces.

The house’s rectangular, two-level core contains pipes and wires in the floor and ductwork and refrigerant in the ceiling. When the pods tap into it using a heavy-duty bolting system, the core “serves” them by supplying their power, water, and more. In this way, space can be added on, subtracted from, or altered in the core easily, drastically changing the way people react to their changing needs for domestic space. As a couple has children, they can add more bedrooms. As the kids go off to college and move away, they can subtract bedrooms and perhaps add a new home theater or office.

The Carnegie Mellon house isn’t just modular in and of itself. Lee envisions it as being able to be unplugged and “played” just about anywhere—a ubiquitous commodity, not a custom-made science experiment. Take, for example, our transient college student. “I like to threaten my students with: ‘Can you imagine if your parents had one of these when you went away to school?’” he says. “They’d just unplug your bedroom and put it on a truck, and you’d simply plug your bedroom in the dormitory core, and it’s just as if you’ve never left home.”

A big class
Beyond the architecture students who are responsible for the design and construction of the house, art students are designing a free-form greenscape sculpture that attaches to the house, drama students are working on the house’s lighting, industrial designers are fabricating kitchen cabinets and the bathroom, and communication students are putting together marketing materials. “I do think I’ll probably see this whole range of people in my career,” says Cathy Chung, an architecture student and lead designer for the house, “so it’s good that I’m learning how to communicate with them and work with them now.”

It’s not just about the wattage
Compared to previous years, the current judging and point system of the decathlon focuses less on objective engineering, such as the amount of electricity raised by the photovoltaic panels that line the house’s flat roof. Instead, they give more weight to subjective architectural values, including passive solar and energy-efficient features like tight insulation, south-facing windows, and natural ventilation.

“The first year, if you made a house that had no passive solar qualities to it and you put a big-ass photovoltaic array [on it] and generated a lot of electricity, you would get more credit for living in a wasteful house than you would for having a small array and putting up a really, really great passive solar design,” Lee says.

“Anyone can take photovoltaic panels and put them on their McMansion and their giant house,” says architecture student and construction manager Brian Kish. “What the construction of this house is really pushing for is energy efficiency.”

Lee says these new guidelines will put Carnegie Mellon’s team in a better position than their 10th place finish in 2005, but that isn’t the team’s primary objective. “We go there trying to represent a holistic idea about the future of housing and the future of the planet,” says Lee. “We don’t go there to get as many points as we can, because we don’t think that a limited focus of reading between the lines and doing gaming and scenario planning and figuring out how to maximize your points is a realistic strategy for a homeowner to follow.”