green design
10:33 am
Wed May 22, 2013

Super-energy efficient homes built to inspire more stringent codes

The homes of the future will come with remarkably low heating bills. At least that's the hope of a Portland-based nonprofit group showcasing 13 super-energy efficient homes in four Northwest states. The question is: can you afford to buy one of these houses?

The model homes are scattered among many of the big cities in Oregon, Washington, Idaho, and Montana. The houses don't look unusual from the outside. But all have been designed to use at least 30 percent less energy.

The makings of a tightly-sealed energy-efficient home

Builder Anthony Maschmedt of Dwell Development showed me around a modern, boxy, single-family home in South Seattle. A bunch of things make this new house super-efficient, starting with heavily-insulated walls, triple-pane windows and a tightly-sealed building envelope.

"If you can make the home airtight, then you're not spending energy heating air, then losing air out the walls. And then spending money to reheat more air that you lose out the walls—it's a vicious cycle,” Maschmedt said.

An exterior spray-on air barrier hides under the siding, says Maschmedt, and there is no fireplace.

“We got away from doing even gas fireplaces, because there's another big hole in the exterior of your house,” he said.

Since this house is virtually airtight, it requires a ventilator with a heat exchanger to circulate fresh air. There is no furnace. Instead, a tankless on-demand water boiler supplies hot water and sends radiant heat through tubes in the floor.

"You have one unit serving two purposes. There is some extra tubing, but that is minimal compared to the cost of having a whole another heating system for your home,” said Maschmedt.

More efficiency at a cost?

Electricians wired each of the homes in the demonstration project with an array of sensors that will track energy use and building performance for the next year. The data flows to a group trying to raise the bar, the nonprofit Northwest Energy Efficiency Alliance, or NEEA. It's funded mostly by utilities.

"You can build more efficiently and you can get to 'net zero.' But what we're trying to do with this specification is really find that sweet spot where you are maximizing energy efficiency—before you start hitting diminishing returns with added costs,” said NEEA's Neil Grigsby, who manages the Next Step Homes project.

Ultimately, Grigsby says his organization wants to put the most cost-effective measures into mandatory state building codes. This concerns Jan Himebaugh, government affairs director of the Building Industry Association of Washington.

Himebaugh says more stringent codes could make new houses less affordable. She favors "a market-driven system" to give builders the "flexibility" to offer better windows for example to home buyers who want that. Other communities could ask for lower-cost new homes.

"Even those that are built exactly to code are much more efficient" than the older housing stock, Himebaugh said.

She added this analogy: "It'd be nice if all had a hybrid car. They get great gas mileage and eventually they do pay themselves off,  or so I'm told. I don't have one. I don't have one, because I can't afford to pay the extra cost upfront right now. And it's the same thing with a home. Many people aren't capable of paying right now."

A 'green' home without an enormous price tag

At this stage, it's hard to pin down the extra cost of building a house that's at least 30 percent more energy-efficient than code.

Olympia homebuilder Scott Bergford estimated a payback period of three to four years for the model home his company built. Bergford's contribution to the demonstration project is a Craftsman-style two-bedroom, three-bath model that his company dubbed the "Inspiration Home."

The home has its own webpage where Bergford explains, "We want people to understand that a 'green' home does not have to have an enormous price tag." 

The modern-style two-bedroom, two-bath home we toured in Seattle cost 5 to 7 percent more to build than traditional construction according to its developer. It sold for $399,000 to Liz Bullard, a mother of three grown children who wanted to downsize. She says she doesn't feel like she paid extra.

"I looked at a lot of houses. There are many, many houses with this same price tag that were much less appealing than this house," she said.

Changing the building code "is a long-term process," says Grigsby. Washington, Oregon, and Idaho update their residential building codes roughly every three years. Grigsby figures his organization will hammer away at its energy efficiency goals for the next three or four code cycles.