Team website: www.cusd.cornell.edu
Coolest features: A building-integrated solar thermal system with a series of evacuated tube collectors along the south exterior of the house that provide thermal energy; and a home control system, accessible through the Internet, that allows residents to monitor power use and turn systems and devices on and off remotely.
Technology/Product highlights: An 8-kW photovoltaic system; an integrated solar thermal system, which heats domestic water; and an entertainment system that features touchscreen monitors and speakers throughout the house.
Anyone can build a cube- or rectangular-shaped house. And in fact, most people build this way. But this year the members of the Cornell University Solar Decathlon team decided to take a different—at least for them—approach to their house.
“Solar Decathlon houses traditionally have a typical appearance,” says Chris Werner, team leader and a Master of Architecture candidate in 2009. “In 2005 and 2007, we built essentially a rectangular house with giant photovoltaic arrays on top. And that’s kind of the nature of the Solar Decathlon house. In 2009, we decided that we wanted to mix it up a little and do something entirely different. It would be new for us and new for the competition.”
Instead, this year the team designed its home as three circular pods organized around a cube-shaped courtyard. “We were interested in doing something that represented local architecture, and what you see all around Ithaca, N.Y., are grain silos,” Werner explains, “so the initial conceptual design is inspired by the bucolic setting. We call it an agricultural industrial aesthetic.
“But we also gave it an architectural kick,” Werner continues. “Instead of using galvanize steel or aluminum, we used Cor-Ten [a corrugated, steel cladding whose outer layer oxidizes to a weather-proof brown].”
The house’s design is hard to miss on the National Mall in Washington, D.C., amid a sea of Solar Decathlon’s boxes. The three rusted Cor-Ten–clad silos each contain a different living space—living room, kitchen, and bedroom and bathroom. Each silo measures 16 feet in diameter, with about 130 square feet of floor space. The school says the modules are joined on the southern side, leaving the northern side open. Large Nana Wall folding doors bring in light.
An 8-kW photovoltaic system helps the house achieve net-zero status—generating more power than it uses—while a series of evacuated tube collectors along the south exterior of the house (installed behind the metal cladding) provides space heating and domestic water heating. Moreover, an Internet-enabled home control system allows future homeowners to monitor power use and turn circuits on and off remotely.The team envisions the Silo House as a vacation house for an empty-nester couple, and it is, in fact, for sale. In the real world, with the cost of materials, labor, and professional fees, one would need to pony up over $725,000 (more than $425,000 in materials, over $200,000 for labor, and over $100,000 in professional fees).
Instead, the team is letting the project go for just $199,000, though the buyer would be responsible for transporting the house, the foundation, the site work, and connecting the house to their own local power grid. These things, the school says, would cost an extra $75,000 or more.
Nigel F. Maynard is a senior editor with Builder magazine.