Can This Home Be Greened? Mountain Metamorphosis: Saving a Colorado A-Frame Home

Enlarge Image Image Gallery The new addition will provide a foundation. Photo Illustration By Andy Johnson

"Can we increase our space and efficiency while also enhancing the connection to our scenic backyard and friendly neighborhood?" 
—Kathy Ellis

Finding an affordable house in Boulder, Colorado, where a small 1940s bungalow can sell for more than $500,000, requires a lot of legwork and even more imagination. The Ellis family felt fortunate to find a house on a half-acre of land in a great part of town with beautiful views. The down side? The 1967 modified A-frame needed an upgrade on every level—starting with the foundation. “We knew we were buying a dream, not a dream home!” Kathy Ellis says. “We had toyed with the idea of doing a tear-down, but that’s just not green.” The question became not so much if this home could be greened, but if it could be saved.

1. The house is barely standing.

Problem: Two of the structure’s load-bearing walls do not connect to the ground. (As strange as that seems, it shows how long a building can last without a solid foundation.) A grade beam is under the house, but one wall cantilevers over the foundation by at least 6 inches, and the opposite “wall” is really the A-frame’s steep roof. The bolts that attach the roof to the floor are actually holding it up.

Solution: The solution to this major problem will become the basis for a redesign. Architect Andy Johnson designed an addition that runs perpendicular to the home’s current east-west axis. The new addition’s foundation can pick up the existing building’s load. The remodel will reverse the existing layout: The current living room will become the garage; the future living area will be part of the new addition. A new foundation under the garage will provide structure for that end of the house.

Cost: Approximately $200,000

2. The old windows are leaky.

Problem: The home’s aluminum-frame and site-built windows conduct so much heat to the outside that they literally freeze the condensation inside, and the windows don’t close properly. The house has so much single-pane glass, primarily facing west, that the wall assembly’s average R-value is probably around R-4.
 
Solution: Fortunately, Boulder is home to one of the country’s best window manufacturers, Serious Materials, which offers foam-filled fiberglass windows with glazing as high as R-14. The company’s operable windows range from R-7 to R-11; a typical low-E window is roughly R-3. Redistributing these windows around the house would allow passive solar gain on the south side and reduce the extensive west glazing, which causes severe overheating. Serious Materials can “tune” windows according to the wall’s orientation. South windows should have a high solar heat gain coefficient to gain passive winter heat. East and west windows should have a low solar heat gain coefficient to keep out summer heat.