Zero-energy home features a living wall of compost
January 12, 2009
By David Hayes
Donna Shirey, like many people, often wondered what happened to all that stuff that gets recycled, particularly the garbage, lawn trimmings and other miscellaneous mulch.
“Well, you can sell some to the Shirey house and build a living wall with it,” she said.
As president and CEO of the Issaquah business Shirey Contracting, Donna and her husband Riley have long been advocates of “green” building. They discovered the services of Cedar Grove Composting fit nicely into their concept for a “zero energy” house.
The Shireys have long owned some property along the western shores of Lake Sammamish, where they are now building their ultimate in green concepts. Essentially, it’s a residence that combines on-site power generation with other measures to reduce energy needs.
Among such amenities as photovoltaic solar panels, a wind turbine, vegetated roof and structural insulated paneling, is the living wall.
Rather than construct an ugly, single-purpose wall made only of concrete at the edge of their driveway, the Shireys called upon the services of Cedar Grove Composting to help build a wall of compost.
A commercial composter, Cedar Grove has exclusive contracts to receive the “green” organic waste King County collects from homes and businesses.
According to Cedar Grove Composting sales manager Jamie Burke, the process has actually been around in other parts of the country for a while and is extremely popular in British Columbia, Canada, roadside projects.
Large, fiber socks, created by a third company, Implied Organics, are filled with the composting material. Structural fill is added to make them more structurally sound and a mesh is wrapped around them to keep them in place. The process is repeated until there are six socks stacked up. The effect is similar to a landscaping keystone wall or boulder wall.
Burke said a test wall was built at Cedar Grove Composting’s Maple Valley site to ensure its effectiveness, difficulty and diversity.
The eight rows, or lifts, of socks are each 18 inches in diameter and are 18 feet long. A total of 20 yards of compost was used to fill all the socks. A smaller 12-inch sock is used for erosion control.
“You then poke a hole in the side, place the seeds, and plants grow,” Donna Shirey said.
Burke said the method the Shireys chose is but one way to take for growing living material out of the wall.
“The beauty of the living wall is you can also seed it before installation and get immediate germination,” Burke said.
Instead of an unsightly, blank concrete wall there is a beautiful structure made from living material adding to the natural setting on the Shireys’ property.
The wall also serves a second purpose, she said. In addition to the aesthetic, it serves as a filter for runoff water heading toward Lake Sammamish.
“We have a water collecting system that feeds the drip irrigation that waters the wall,” she said. “The wall then holds back silt with harmful materials that would have naturally flowed to Lake Sammamish.”
Burke added that Cedar Grove placed composting blankets on the construction site and a filter sock every 50 feet to prevent erosion and slow runoff into the lake.
“With the heavy rains we just had, the composting proved to be a good example of handling storm water,” Burke said.
Construction on their zero energy home began in August and the Shireys hope to have it complete by April, when they plan to open it for public tours.
“It’s geared toward consumers as a high performance house,” she said.
As advocates of green construction techniques, the Shireys hope their home inspires others to incorporate such eco-friendly innovations as the living wall into their future residential plans.
Burke said she suspects with the interest generated with the project, by this time next year, living walls will be standard practice.
“It’s a great use of recycled material, especially for our region, where it has become more and more important for residents who prefer to build green,” she said.
Reach Reporter David Hayes at 392-6434, ext. 237 or email@example.com. Comment on this story at www.issaquahpress.com.