Although Sykes admits a home like this costs 10 to 15 percent more than a typical stick-frame house, he says that when one factors in other life-cycle considerations, such as the cost of repairing and replacing mechanical systems, the Durham home and others like it are cost effective. The basic kit for the same model as the Durham house is sold for just more than $109,000. This includes the exterior wood, interior walls, posts, door frames, girders, beams and rafters. The owner or builder supplies the foundation, main floor, partition framing, windows, doors, stairs, flooring, ceiling, roof, plumbing, wiring and cabinets. In part because of its near-city location, the Durham house, in total, cost about $350,000.
The Durham house used solid southern yellow pine timbers, which were treated with borax mineral crystals that offer more efficient storage and release of passive solar energy. Enertia Building Systems now has switched to glulams, which are glue-laminated wood blocks that can be built out of scrap lumber and resist warping and cracking, making them more durable than logs. The wood for the glulams is sustainably harvested, and the glulam manufacturer asserts that two or more trees are planted for every one cut down. “Changing to glulams has made the kit more costly, but the builders have reported to us that the time to assemble the house is cut in half because glulams are straighter and of more perfect quality,” Sykes says. “Since every foot is usable, we cut our scrap from 30 percent down to less than 1 percent.”
Although his distinctive houses do not readily fit into the Washington-based U.S. Green Building Council’s LEED certification or most other greenrating systems, Sykes asserts that the homes are truly sustainable by their inherent design. “Once you choose to make your walls out of wood, you eliminate about five major green-building decisions, such as choosing siding, framing, insulation, inside finish and paint,” Sykes says. “All are replaced by one renewable building block. Future builders will see these blocks and make another house out of them. We’re pretty confident that these blocks will always be more valuable as structural components than as landfill fodder. This wood actually is a cradle-to-cradle component.”
Energy Costs: In 2006, the 1,526 square foot (143 m2) Durham house had a total energy expenditure of $572. Electric: $35 per month ($420 annually). Gas $80 in January and $72 in February ($152 annually).
Kim A. O’Connell writes about architecture and sustainability from Arlington, Va.
DURHAM HOUSE / DURHAM, N.C.
DESIGNER AND BUILDER / Enertia Building Systems Inc.,
Youngsville, N.C., www.enertia.com
GENERAL CONTRACTOR / South Grown Building & Timber
Frame Co., Hillsborough, N.C., www.sgtimberframe.com
SOLAR-PANEL INSTALLATION / Solar Consultants, Carrboro,
GLULAMS / Anthony Forest Products, El Dorado, Ark., www.anthonyforest.com
BACK-UP WOODSTOVE / Fireplace Editions, Chapel Hill, N.C., www.fireplaceeditions.com