The House Designed To Pay Your Energy Bill Actually Works

Dec 4, 2015

Wouldn't it be nice to get a check from your electric utility instead of a bill? That's exactly what happens for a select few homeowners in the Pacific Northwest whose solar-powered houses generate more electricity than they use over the course of the year.

One place to see how this works is at a super-efficient townhome development outside Seattle, which was designed to be "net zero energy." And that claim has now been audited.

When the sun comes out from behind the clouds, cool things happen at Karin Weekly and Bryan Bell's townhome in Issaquah, Washington. Not only does it get brighter in the couple's airy living room, but their electric meter starts running backwards.

"Right now our energy meter is showing negative 3,800 watts about,” Bell said as he glanced at a digital readout in his kitchen on a recent morning. “That's because the solar panels on the roof are generating that electricity."

Bell said his two bedroom, two bath home includes lots of energy and water saving features. Much of the year, the rooftop solar array generates more electricity than he and his wife consume. The surplus goes back to the power company.

"This year we got a check for $1,100 for selling our energy back to the grid,” he said. “That was very nice!”

From experimental to mainstream?

And it's better than the project developer's goal of netting out to zero over the course of a year. Hence the development's name: zHome.

The complex with 10 highly-insulated units around a courtyard came on the market in 2011. It took a while to reach full occupancy because of recovery from the recession and above average sticker prices for the townhomes. But the demonstration project now has a track record that can be examined.

Built Green Program Manager Leah Missik wrote a white paper for the local homebuilders chapter, the Master Builders Association of King and Snohomish Counties.

"Originally, zHome was lauded as the first net zero energy townhome complex in the country,” she said. “But that was based on energy models, not actual occupant behavior, which of course you don't know until a few years later. We managed to get that data and analyze it, which is a pretty rare thing. We were really happy to find that zHome in fact did meet its expectations."

Missik said the complex as a whole produced 3.5 percent more electricity than it consumed between April 2013 and April 2015.

Its residents also used about 70 percent less city water than average suburbanites. zHome units capture rainwater in cisterns, which is filtered and then used for toilet flushing, laundry and garden hoses.

This project was subsidized with free land by the city of Issaquah to inspire homebuilders to aim higher.

So, did it catalyze more super-green building?

“We are seeing a lot more projects of this type -- maybe not with this number of units and with this depth of green,” Missik's boss at the Master Builders Association, Aaron Adelstein said. “But we’re seeing a lot of projects using technologies that were used here in more mainstream speculative projects.”

Stuff like ventilation heat exchangers, high performing appliances and radiant floor heating are winning greater acceptance. However, Adelstein said the geothermal heat pump used to cut heating costs in the zHomes "has fallen out of favor a little bit." Air source heat pumps which don't involve drilling into the ground are much cheaper and nearly as efficient.

"Since this project, solar panel pricing has come down pretty significantly and we're seeing that applied on a lot more projects,” Adelstein added.

"There are different levels of Built Green; there's a 3-star level, a 4-star level, 5-star level,” Adelstein continued. “Certifications at any level within the city of Seattle were 58 percent of the new (residential) construction in Seattle in 2014. You can't attribute all of that growth to this project, but it is a piece of the puzzle."

It’s not easy being (super) green

A separate green building certifying organization named International Living Future Institute also crows of momentum. ILFI, which has offices in Seattle and Portland, sets standards for net zero energy building as well as a more comprehensive benchmark called the Living Building Challenge. The Living Building badge may be the industry's toughest to achieve in that it demands not just net zero energy, but to be "net positive" for energy and water, meaning the project should produce more than it uses.

The Living Building Challenge also requires wastewater to be treated on site and for builders to use only non-toxic construction materials.

"We are truly experiencing an exponential rate of growth with the Living Building Challenge," said Brad Liljequist, technical director at the International Living Future Institute in Seattle. "We have 310 projects worldwide that are pursuing the challenge and an average of two new registrants per week."

Online maps show where in the Northwest net zero homes have been built. They are still few in number -- just a few dozen homes or developments and commercial projects in our region. And nearly all are along the Interstate 5 corridor: Vancouver, BC, greater Seattle and around Portland. A few in Bend, Oregon too.

Adelstein said that's a function of where affluence and growth is concentrated.

‘No buyer's remorse'

Bell and Weekly said they didn't set out to buy a green townhome, but are glad they did.

"We have loved it since we came in,” Weekly said. “We have had no buyer's remorse for a moment yet, which I think is unusual and great for a new homeowner.”

Bell and Weekly said they paid $400,000 for their zHome and moved in in July 2014. They are the second owner of their unit. The three story townhome has an open floor plan, loft bedroom and a music room on ground floor.

"We didn't feel like we were paying a premium to get this place," Bell said. The homeowners' association dues are higher for the complex than for comparable homes elsewhere in their suburb Weekly added, but offset by energy savings.

The couple said that living in the zHome has made them more conscientious about their energy usage but they don't feel like they have had to make sacrifices. Weekly, 46, works as a database engineer at Microsoft and teaches piano on the side. Bell, 49, described himself as a "house husband."

"Historically, zero energy was the province of high-end, custom construction where you had a very deep green homeowner that was willing to spend whatever it took to get to that benchmark," Adelstein said. "It doesn't take spending whatever it takes anymore."

In the Seattle market, he estimated the price premium around 8 to 12 percent in aggregate; less than that in outlying county neighborhoods. "Because of increasing consumer interest, we're seeing more projects take that step," Adelstein observed.

More net zero projects: notable and infamous

Liljequist listed some other notable net zero energy projects which were completed in Northwest in the last few years. Probably the best known is a commercial building, the six-story Bullitt Center in Seattle, which is the largest building in the world to achieve Living Building Challenge certification. He also called out the new music and science wing of Hood River Middle School in Oregon, where documented energy generation slightly exceeded actual use in the year after opening.

In Northwest Washington, Liljequist said the Lopez Community Land Trust won grant funding to help construct an affordable net zero community. The mixed-income development has 11 homes and two rental units along with an office.

A cautionary tale comes from Portland where more than five years ago the city and state harbored ambitions to build a high-rise showcase for net zero energy efficiency and green technology at Portland State University. The proposed Oregon Sustainability Center would have relied heavily on taxpayer financing, which proved its downfall.

The project was scrubbed when neither the state nor city could figure out how to make the $62 million building pencil out.