When Washington builders Donna and Riley Shirey decided to build the Zero Energy Idea House in Bellevue, they were determined to create an educational “laboratory” that would demonstrate a wide range of green and sustainable possibilities.
“It was our chance to show how to build a high-performance house and create a real teaching tool,” says Donna about their decision to build the home that would push the envelope beyond what Shirey Construction had attempted in its more than 25 years building energy-efficient SIPs dwellings.
But before they could break ground and begin construction, the Shireys had to address a long list of issues related to the lakeside site. Along with a slope “so steep and overgrown you couldn’t see the bottom,” says architect David Clinkston, the property came under a new Critical Areas ordinance that placed strict limitations on development impacts in environmentally sensitive areas.
The good news was the ordinance dovetailed with the project goals of demonstrating principles of low-impact development. The bad news was it required an extended team of experienced professionals—including several engineers, a land-use planner, two landscape architecture firms, and a wildlife biologist—three extra months and a consulting budget of $75,000 to solve the problems. Among the challenges they faced: building a foundation
on the 65% slope that required 14 tons of rebar and 200 cubic yards of concrete.
Next came the critical low-impact variable of erosion control. “We couldn’t just have water flowing down the slope—we had to manage it,” says Shirey. To that end, 18-inch-diameter compost socks—mesh tubes filled with composted material—were installed down the north side of the driveway to help retain sediment, and a 1,000-square-foot vegetated green roof was introduced to help reduce stormwater runoff. They also used downspouts to collect water for the cistern.