Sustainable in the City
Three years ago, Seattle-based builder and remodeler Sloan Ritchie founded Cascade Built, a green construction company, with the goal of creating contemporary, sustainable urban homes. After completing a town home project that was one of the first in the country to achieve Silver level certification from LEED (Leadership in Energy and Environmental Design), a green rating system developed by the U.S. Green Building Council, he set his goals higher. “I wanted to continue to push the envelope,” he says, “and one day I’d like to build a Net Zero home.” The goal of such a home is to essentially cut the energy bill right down to zero, by balancing out the amount of energy the home produces to how much is used.
He’s coming close. Ritchie’s latest project, which he calls Alley House, has received a LEED Platinum rating, the highest available. The 1,900-square-foot home is located on an in-fill lot (meaning it’s in an existing neighborhood) one mile from downtown Seattle.
The lot itself is only 2,000 square feet in size, so Ritchie had the challenge of making the most of the space. Building a taller, three-story home rather than a two-story one with a larger footprint was an early design decision.
Constructed of structural insulated panels (SIPs), the home is well insulated to cut down on energy use in the winter. It has a five-zone radiant floor heating system fired by natural gas and no mechanical cooling system, due both to the city’s mild climate and the placement of windows and roof overhangs designed to shade the home from the sun in the summer. A 400-square-foot green roof over a section of the home’s second level also helps with cooling.
The green roof has additional benefits as well. For instance, most people don’t realize that a green roof can double or triple the life of a roofing system, Ritchie says. What’s more, the green roof’s soil and plantings (Ritchie used drought-tolerant sedum) aid in moisture evaporation and help prevent ultraviolet rays from breaking down the roofing membrane.
The home’s other green features include a solar thermal system, which heats hot water on sunny days. A tankless, on-demand water heater, as well as a natural gas water heater, provides backup hot water for the home’s radiant heating system and for domestic use.
Not all of the home’s green innovations are expensive or complicated. One feature Ritchie is particularly proud of is a drain-water heat recovery system. Ritchie installed a product called Power-Pipe, which recycles warm wastewater from the shower drain, sending it through a thin copper coil that is wrapped around the shower’s cold-water supply pipe, and raising the temperature of the cold water before it hits the shower nozzle. “This is super low-tech,” Ritchie points out, “but it’s 50 percent efficient. In two seconds you can turn your hot water valve down by half.”
Being green also means being healthy, and this residence meets the grade. Ritchie used a formaldehyde-free oriented strand board (OSB) in the subfloor, and paints and stains that have no volatile organic compounds. Cabinets were constructed from Medex, a formaldehyde-free medium-density fiberboard panel made from post-industrial recycled wood fiber. Countertops in the bathrooms and kitchen are CaesarStone quartz composite surfaces. The floor for the first level is pigmented concrete with a rich black color. Ritchie used bamboo for the courtyard deck.
Another unique feature of this residence, which many people often overlook, is its location. Situated in an area zoned for density, the home is within easy walking distance of shops, restaurants and city transportation, so the homeowners will not need to use their personal automobile very often. “Some people don’t think about a home’s walkability in terms of energy savings,” Ritchie says.
Ritchie expects the residence to save 50-60 percent in energy costs, compared to a conventionally built home of the same dimensions. Completed in August, the home is currently available for sale, and is listed at $770,000.