Super Efficient Energy
A Rainier Vallery homeowner employs the common sense - and human powered - Passive House standard.
By Seattle Mag
September 12, 2011
The first time Dan Whitmore welcomed a group of friends to the nearly completed Rainier Valley home he was building for his family, it was a bit like a treasure hunt.
“It was our first blower door test,” says the goateed contractor. (A blower door test is performed to check airtightness of a house and is done with a fan that creates a pressure change.) “There were 15 people running around looking for air leaks.” This summer, Whitmore completed Seattle’s first single family home to meet a super-energy-saving building standard from Europe called Passivhaus (or, in the U.S., Passive House).
Passivhaus, developed in Germany in the early 1990s, emphasizes building a structure so thickly insulated and carefully sealed that it requires little to no supplemental heating or cooling in any season. It was an idea that made sense to Whitmore, who grew up in Oklahoma with professor parents in a solar-powered home.
“I like the idea of limiting the energy we use here in our country, so we don’t have to go looking for energy in other countries,” he says. Whitmore was also inspired by his work in the 1990s as a disaster assistance inspector for the Federal Emergency Management Agency (FEMA) in Florida and Puerto Rico, where he learned the wisdom of keeping climate change and regional hazards in mind when building.
Like other houses built to the Passive House standard, this one should prove at least 75 percent more efficient than a standard, built-to-code house. Though Whitmore’s home has only been occupied for a couple of months, the house is built to remain a pleasant 68 degrees through the colder months, mostly by way of the heat radiating from a few appliances and the sun. The other source of energy? Us.
“We humans are giving off the heat of a 100-watt light bulb,” Whitmore says. “It’s enough to take care of the vast majority of our heating needs.”
To keep heat from escaping, house walls are 14 inches thick, rather than the 5.5-inch thickness of new construction.
The polished concrete floor on the main level is insulated with five times the standard amount of eco-friendly foam. House foundations aren’t usually insulated from below, but this one is, with another 4 inches of foam.
Windows are triple-paned, argon filled and specially glazed to trap the sun’s warmth. Passive houses also require special ventilation. Whitmore uses an Ultimate Air RecoupAerator, which constantly vents stale air from kitchen, bath and laundry, and brings in fresh outdoor air.
But does it really stay warm when it’s 20 degrees outside?
Whitmore has a couple of space heaters for the coldest nights, and he can always just invite those 15 friends back and trap their heat. “It brings new meaning to the phrase ‘housewarming party,’” he says.
What you can do:
Quick fix: Insulate and air-seal your outlets. As blower tests show, anywhere you have air leaks in your house you’re losing valuable heat, and outlets are an overlooked spot. Thin foam insulation pads, which fit beneath outlet covers (and go around sockets), are very cheap, easy to install and available at most big-box stores. (Don’t forget to turn off the power to the socket before beginning this project.)
Weekend project: If you can see daylight around doors, window frames or your mail slot, you have leaks. Use caulk or weather stripping to fill the gaps.
Long term: Get an in-home energy audit subsidized by Seattle City Light. For approximately $100 (or free if you qualify), auditors come to your house and check for leaks, insulation and heater efficiency. Use the information to make changes that will cut heating costs (seattle.gov/light/conserve/hea).