Thursday, September 10, 2009

Solar Decathlon provides UI students experience creating sustainable house

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Solar Decathlon provides UI students experience creating sustainable house

[Information about this weekend's open house available at the Gable Home web site:]

Over the course of the past three months, students and faculty advisors from the University of Illinois have been completing construction of a small house near the College of ACES library on campus in Urbana. With an interior area of only 565 square feet, it’s a much smaller structure than most Americans might picture in association with the word “house.” But it’s certainly a building with many stories.

One important story is its reason for being. The Gable Home, as it is called, is not meant for a family to live in, but to represent the U of I at the 2009 Solar Decathlon. This competition, sponsored by the U.S. Department of Energy, will bring together 20 teams from select post-secondary institutions around the world to set up houses on the National Mall in Washington D.C. in October. [Photos: upper, the house nearly ready for visitors; lower, solar panels being installed back in July.] Entries in the contest will be judged by their architectural integrity and aesthetic appeal, as well as how they meet demands for energy.

The most practical way to make a house that can meet all of its energy needs with solar power is to greatly reduce those needs through conservation. Thus the creators of the Gable Home are aiming for the most rigorous current benchmark for energy efficiency in building, the Passive House standard. Adherence to this standard, which is widely employed in Europe, and is promoted by the Passive House Institute U.S. located right in Urbana, reduces energy use by 90% compared to conventional construction.

The Gable Home minimizes thermal losses by means of exterior walls that incorporate an extraordinary amount of insulation, from about 9” where they are thinnest to 14” where they’re thickest. The innovative framing used in the walls, a thin bamboo laminate called Lamboo, was chosen over steel because it conducts less heat between the interior and exterior of the house than steel would.

The windows of the Gable Home, which comprise three panes of glass in an argon filled frame, also serve to prevent thermal loss better than standard double panes. In addition, the windows on the south wall of the house are much larger than those on the north, which will allow it to take advantage of the free heat provided by the low sun in winter.

Conserving energy is only part of the game at the Solar Decathlon, since teams also earn points by performing the tasks of everyday life, including cooking, washing dishes and doing laundry, as well as running a computer and a television. The creators of the Gable Home anticipate that it will generate more electricity than it uses by means of the solar panels on its roof. This will earn them points in the competition and enable them to sell electricity back to the grid over the life of the house.

To the credit of everyone involved, the Gable Home is characterized by attention to issues of sustainability beyond energy use. Its exterior siding is made from wood that was salvaged from a barn on the family farm of student working on the project. Similarly, the deck around the house and the handicapped-accessible ramp leading up to it are constructed with wood that was reclaimed from a grain elevator taken down in west Champaign last year. The new products used to finish the house, from the paint to the flooring to the furniture were also selected with regard to their environmental impact.

While the Gable Home won’t actually provide anyone with a place to live, the process of creating it has provided some 200 University of Illinois students from many different disciplines with direct experience in the design and construction of a sustainable house.