The owners wanted a beautiful home that could also educate the public about energy-efficient building. Twelve-inch thick structural insulated panel walls give the home a feeling of mass and permanence.
Custom details include built-in shelving and cubbies, and metal stairs. The thick walls reduce temperature swings indoors.
Passive solar satisfies 90 percent of the heat and hot water demand. In sub-zero weather, the house will never drop below 58 degrees. Fiberglass-framed windows are R-11. South-facing windows capture sun, but include motorized blinds for night time.
The kitchen has water-saving faucets, low-VOC cabinets and Energy Star appliances. Hot water pipes are insulated, and a recovery system collects heat from the waste water drain in the master bath. A recirculation system provides instant hot water.
The walls are R-48, and with additional foam insulation the roof is R-68. Roof-top solar panels flow hot water to two 5,000-gal. underground cement tanks that store heat for months. Massive overhangs shade windows and patio spaces from summer heat.