NFRC News Now recently visited a solar-powered house bound for the U.S. Department of Energy’s 2013 Solar Decathlon competition this fall to get a sneak-peek at its high-performance fenestration. The "Harvest House” is being built on a parking lot at Catholic University just 10 miles from NFRC’s headquarters.

Project Manager Bobby Blabolil and Revit Manager Jeremy Haak conducted a tour for NFRC’s Tom Herron and Jessica Finn, pointing out the house’s high-performance features, including its energy-efficient windows and doors.

Students from Catholic University of America, George Washington University, and American University have joined together to form Team Capitol DC to build the house, which they have entered into the Solar Decathlon. This year’s competition will take place in Southern California, marking the first time the event will be held outside of the nation’s capital. The competition challenges college students to build well-designed, highly efficient, and comfortable homes that are only powered by the sun.

High-Performance Fenestration

All of the windows in the Harvest House are custom-built and NFRC-certified. The windows are double-pane, argon filled. The Sanders Company was the window distributor, and NFRC participant, Western Windows Systems, manufactured the windows.

The team installed large windows and doors on the south and north sides of the 850-square-foot house to let in a good deal of daylight, to allow a cross breeze, and to provide a view to the outdoors from the living room. The windows and door on the house’s south side have NFRC ratings of .38 for U-factor, .22 for Solar Heat Gain Coefficient (SHGC), and .51 for Visible Transmittance (VT.) The south-facing glazing will feature a passive, louvered exterior shading system to help lessen the intensity of the warm California sun.

The windows and door on the north side have NFRC ratings of .51 for U-factor, .19 for SHGC, and .39 for VT. The operable window on the east side of the house has NFRC ratings of .45 for U-factor, .18 for SHGC, and .4 for VT. And, the east door has NFRC ratings of .33 for U-factor, .24 for SHGC, and .55 for VT.

The team considered triple-pane windows, but decided that the extra cost was not reason enough for the incremental improvement in energy performance. Part of the judging criteria for this competition involves affordability. Blabolil explained that it may have been a different consideration if the event took place in a colder climate, but the team was less concerned about U-factor for a house that will be sited in Southern California.

A Good Deed

The net-zero-energy house is designed to be accessible to someone with a disability. For example, the door sills are ADA-accessible allowing for easier wheelchair access than a traditional sill. Following the competition, Team Capitol DC plans to donate Harvest House to a U.S. war veteran.