Zero Energy Homes
One of the interesting booths at the Seattle Home Show was the Zero Energy Idea House, sponsored by Shirley Contracting. The Zero Energy Idea House is designed to show that smart choices can result in a home that minimizes energy use, while maximizing comfort and style.
I talked with Riley Shirley, VP of Shirley Contracting, about the project. The house is for him and his wife Donna. They are trying to prove that it is possible to build a house in the Puget Sound that uses as little energy from the utilities as possible. They are also trying to use as many sustainable resources for this construction as possible. The list of partners is impressive.
They achieve this goal by building intelligently. They make use of insulated concrete forms for the foundation:
A portion of the foundation is constructed of insulated concrete forms, or ICFs. ICFs use expanded polystyrene with concrete poured in the middle after rebar has been inserted for reinforcement. The result is a strong foundation wall that uses less concrete and is fully insulated.
To insulate the upstairs, they make use of structural insulated panels, a sandwich of 2 OSB sheets with expanded polystyrene foam between them. The panels are a good 6.5 to 10.5 inches thick. The panels can have openings for doors and windows precut, and conduits in place for electrical wiring already in place, ready to go. You just send your architectural plans to the manufacturer of the panels and they create a collection of numbered, custom cut panels ready to be assembled on site in fairly short order.
Another innovation that is being used by the Zero Energy Idea House is the compost filled “living wall” using the Greenloxx™ wall system created by Filtrexx. This system makes use of a nylon mesh sock that is filled with a special compost mixture to help promote plant growth, laid in rows forming the retaining walls. One sock can weigh as much as 1,200 pounds.
The north side of the house features a “living wall” installed by Applied Organics. It’s a structurally engineered installation that combines compost (supplied by Cedar Grove Compost) with special netting for reinforcement. Add plants, and you’ve got an attractive alternative to a concrete or masonry retaining wall that also absorbs storm water and produces oxygen. As the plants grow, their root systems make the wall even stronger.
To power the house, they will make use of solar energy as the primary source of power. The contractor in charge of implementing this plan is Mitchell Mechanical. In all they plan to use the following:
- Radiant heat with hydronic heat pump (heat)
- Solar Thermal hot water system (hot water)
- Solar Photovoltaic system (electricity)
- High efficiency hot water tank (back up hot water/heat)
To decorate the house, they plan to use as much sustainably harvested lumber as possible, along with recycled tiles, low VOC paint, and other sustainable materials. The house is still being constructed, but when it’s finished, it should be a site to see.