Creating a Net-Zero Nest

By Brian Libby
Photography by Mark Woods Photography

Whether it’s to save money on energy, to save the planet or to have a resilient safe-haven when the big earthquake comes, net-zero-energy and passive houses have never been more popular.

The culture of the Pacific Northwest has always been given to ecology. Living amid our millions of acres of forests, beneath our snow-capped peaks and beside the mighty Pacific, the region’s beauty inspires us not only to leave the city behind from time to time and commune with nature, but also to conserve and protect those wonders. Green design and construction is a way to embody those values in what we build: using less energy and relying on sustainably-harvested woods and other low-impact materials.

Today, many homeowners are taking these efforts a step further, creating abodes that can use alternative energy, such as solar, to generate as much power as they use (known as net-zero energy) or creating enough of an air-tight building envelope (known as passive-house construction) to use as little as ten percent of the power necessary for a conventional building.

“There’s been growing interest,” says Jeff Stern, a Portland architect specializing in passive-house construction. “It’s still certainly a niche, but it’s moving a little bit toward the mainstream.” There is added cost in building robustly, he says—generally about five-to-ten percent—but there is also the opportunity to save.

Yet building a sustainably designed home isn’t just about conserving and saving energy, experts say. It’s about comfort. “The whole concept around the passive house is that you can walk around in socks and a t-shirt and you don’t have to go to the thermostat to make it comfortable,” explains Daniel Thomas, co-owner of Hammer & Hand, a Seattle and Portland-based builder specializing in green architecture.

Both Thomas and Stern emphasize that it’s better to focus on conserving energy first and then to consider alternative energy sources like solar. “For us, there’s a series of graduated steps,” Thomas says. It starts with placing a home so it’s able to take in as much south-facing light as possible. Then it’s about windows. “Are you using double pane windows? Have you explored triple-pane windows, which have this tremendous effect on comfort? Then it’s about insulation,” he adds. “Places like the Cascades or the Columbia Gorge get really cold. Are you going to use a continuous skin of insulation on the outside?”

At the same time, there’s never been a better time to look at solar power. The Wall Street Journal reports that the price of solar panels has dropped by 20 percent in the last year alone, and, according to statistics from the International Energy Agency, purchase agreement prices for solar power have dropped by about 75 percent over the last seven years. Today, one doesn’t even have to purchase solar panels, which tend to last about 20 years; a variety of programs exist to rent them from power companies. And a new generation of batteries is emerging that allows homeowners to store by night the energy that the panels generate by day.

 “Just like chips were annually doubling in size and dropping in cost, solar is too,” Thomas says. “On every predictive model about solar costs and efficiency, cost keeps dropping. The hope is that it becomes so efficient that it will replace fossil fuels at a per BTU cost. It’s not there yet, but it is making significant inroads.

When one combines a robust building-envelope through passive-house construction with alternative energy sources like solar or wind, as well as other sustainable design moves like capturing rainwater, it can add up to what may be the most attractive feature to owners of a first or second home: resilience. Besides saving energy, a well-designed building envelope can also keep out rodents and insects, while adding an extra layer of protection against water intrusion. All of which can mean fewer repairs and fewer headaches along with added comfort and reduced power bills. “Building a good envelope means if it’s done well it just makes for a more durable building,” says Stern. 

And Stern would know: He lives in his own passive house. “I pretty much never turn the heat on all winter long,” he says. “It may get down to 62 or 64 degrees. But just having a really good building envelope and not having those leaks creates this baseline that’s very warm and very comfortable. Focusing on the envelope is ideal for a vacation home. You worry less about pipes freezing or condensation or mold, just because the interior temperature is going to stay quite mild even with very little heat input.” In the summer, the home stays cool without air conditioning.

Therein lies the appeal of these techniques: They do cost more, but they pay back in the pocketbook, in comfort and in better energy management.