Lessons Learned From an Early Adopter of Sustainable Home Design

Another was for daylighting. The double-glazed, Low-E, and argon-filled windows were positioned to bring in maximum sunlight, and designed with enough glazing to minimize the use of artificial light during the day. In 2008, the windows installed exceeded Seattle’s progressive energy code, Piper says.

The house’s design is comprised of a simple series of stacked, offset volumes. The ground floor has a central services core in the middle that includes the powder room and stairwell. Airy living and dining areas open to the backyard. “Putting services at the central core allowed us to make the edges of the building more transparent,” Piper says, “to steal space from the outside to bring inside, and emphasize the relationship between the building and the site.”

The house opens to the back, which is quieter than the front aligned along a busy street. On the second level, the bedrooms are on the south side, with a hallway on the north side. The top floor, where the master suite and office are located, is open to the south and west to allow in more light. Fivedot clad the house in tight-knot cedar, which “at the time was a relatively affordable product,” Piper says.

At the front of the house, along the high-traffic street, Fivedot placed several concrete tanks that act as a sound barrier, create an entry court, and hold rainwater from the home’s rainwater collection system. "The house doesn’t hide its sustainable aspects but shows them off proudly, as design features that add to its unique and intensely local quality," says Piper.

Rainwater is collected off the roof and funneled into the tanks, filtered and treated, and brought back into the house for flushing toilets and for use in the washing machine. “Reduced water usage means less potable water gets flushed into the sewage system,” Piper adds.

Inside the home, an on-demand gas-fired boiler provides radiant heat installed beneath the floors. A solar hot water pre-heat tank heats the water. The concrete floors on the first level include 15 percent fly ash, a by-product of coal production. The casework was crafted by Kerf Design in Seattle, using only formaldehyde-free, sustainably harvested, Forest Stewardship Council (FSC) certified wood.

The kitchen and bath tile contain recycled content. The fireplace surround and countertops are from Paperstone, a solid-surface material made from post-consumer recycled paper. The open stairway and floors on the upper levels are bamboo, a fast-growing material that’s sustainably harvested.

Throughout the home, low-VOC paint, formaldehyde-free plywood, and prefinished floors minimize off-gassing. The radiant-floor heating eliminates the need for air ducts that can accumulate and redistribute dust and other particulates throughout the house.

“The design is fairly simple and uncomplicated, but rectilinear and straight,” Piper says. “To offset that angularity, we incorporated moments of beauty in the interior décor—often using repurposed or salvaged items—to provide more soft-edge contrasts.”

In the powder room, Fivedot installed a polished, live-edge slab as a counter, which was harvested by colleague from a tree that came down near the city courthouse. The first-level coat closet is covered with two reclaimed doors, mounted on a sliding track, from a salvage yard. A coffee table of reclaimed fir by Urban Hardwoods in Seattle is the focus of the living room.

Looking Back

What did they miss? And what would Fivedot do differently, a decade since the house’s completion? Four things.

1. “We designed the roof on the lowest volume to be a green roof, which wasn’t installed for financial reasons,” Piper says. “A green or live roof would have increased the insulation value, which was already high, and also served as a way to contain water before it moved into the ground.” 
2. With more capital, Piper adds, “we would also have installed exterior insulation on the plane of the exterior, not just in the wall cavities and roof: rigid foam or Rockwool. One way you lose quite a bit of energy out of the home is through the physical movement of air through the envelope to the outside. Rigid insulation can be taped, creating a tight air barrier, providing higher performance over time.”
3. Fivedot also would have nixed bringing treated rainwater back into the house for toilet flushing and clothes washing. “The health code requires a separate set of lines in order to bring water treated on-site back into the house,” Piper explains, “to prevent any untreated water from contaminating the city system. Installing the separate lines and water treatment system was expensive. The water used isn’t really that much, so the utility was limited for the amount of money it cost.”
4. Finally, Fivedot would have liked to build an ADU. “This site would have been perfect for that,” Piper says. “At the time, city code didn’t allow for it. Now, it’s permitted.”

Still, Built Green, a holistic sustainable home certification program of the Master Builders Association of King and Snohomish counties in Washington state, gave the home a four-star certification. Moreover, every project is a learning experience. Piper says. “We’ve taken a myriad small details from this house forward into other projects.”

There are always tradeoffs when it comes to home building and remodeling. One lesson for home professionals? It’s always helpful to revisit projects and wonder: knowing what we know now, what would we have done differently?