This Colorado community is already living in the all-electric future

From inside his all-electric home, Klebl explains how he designed the buildings. His recipe comes down to three key ingredients: a high-performing building envelope, an orientation that harvests free heat from the sun, and all-electric equipment — especially wildly efficient heat pumps.

All of the Geos homes are built based on Passive House design, which focuses on creating a tight ​“building envelope” that makes a home well-sealed and insulated, like a beverage cooler. Their walls are constructed with foam and blown-in cellulose. Residents look out through triple-pane windows that are three times as energy efficient as double-pane ones, Klebl says. (The ability of something to resist the flow of heat is given in R-values: the higher the number, the more insulated. Geos homes have an R-15 slab foundation, R-28 walls, R-42 roofs and R-6 windows.)

The building envelope’s design alone reduces heating and cooling costs by half compared to typical construction, Klebl says, and it’s a key reason I feel perfectly toasty inside Klebl’s home even on a frigid day. 

The building’s tight, insulated construction also keeps it very quiet. Through the living room’s picture window, I can see the snow being whipped by the wind outside, but I can’t hear the howl. Inside, it’s incredibly peaceful.

The homes here are also oriented to heat passively. They soak in sunlight that streams through their south-facing windows, which can reduce heating costs by a whopping one-third, Klebl says. Most typical homes in the area have their big windows facing west for views of the Rocky Mountains, he adds. But that design means homes get little heat in the wintertime, ​“and then they get a lot of heat in the summertime.”

Geos has a mix of housing types, including townhouses and stand-alone single-family units. The single-family homes are offset like checkers on a board so they don’t shade each other.

The homes also use solar energy in another way: to generate power using photovoltaic panels. Depending on their size, the homes each have a PV system of between 4.5 and 6 kilowatts.

And finally, every home comes with fully electrified, efficient appliances, which can be powered by the solar panels.

The 2,500-square-foot single-family homes utilize more efficient geothermal or ground-source heat pumps. Through pipes that delve 300 feet underground, they leverage the earth’s fairly constant temperature of about 55°F here. That’s a much easier starting point for home heating than, say, 20˚F winter air.

Other electric appliances abound. Heat-pump water heaters deliver the hot showers. Residents dry their clothes with heat-pump dryers. And they cook on electric induction stoves, the speed of which astonishes homeowner Vince Parker. ​“It gets hot so fast,” he says. ​“I mean, if you’re boiling water, it’s just 30 seconds.” The garages also come equipped with 240-volt outlets that residents can use with portable charging cables to power their EVs.

Plus, Klebl wanted to ensure that Geos homes, airtight as they are, wouldn’t get stuffy, he says. Most homes breathe through the cracks in their shell. But to fill a Geos home with fresh air, Klebl gave it a set of lungs: an energy-saving device called a conditioning energy recovery ventilator, or CERV.

A CERV harvests thermal energy from the air leaving your home and uses it to precool or preheat filtered air coming in. The machine also comes with a small air-source heat pump to bring the air to the desired temperature; the smallest Geos homes don’t even need a separate heat pump for heating and cooling.

CERVs also make the built environment healthier for residents, Klebl points out. Stale air can concentrate pollutants that can make us sluggish, dull — or even sick.

“I have little kids; I worry all the time about the air they’re breathing,” says Sara Kuntzler, Colorado program director of climate and environment grassroots group Mountain Mamas, who joined the tour, in part to see what technology in use at Geos could be adopted by the board of the local school district, Jefferson County Public Schools.

“They need this kind of information,” she says.

A startup to make other homes net-zero like Geos 

The Geos community was initially planned to host 282 net-zero homes — not just the 28 homes here now.

But Klebl’s original vision stalled in 2020, when he had to sell a large parcel of the undeveloped Geos land as part of his divorce settlement. The developer who took over ultimately decided homes piped with gas would net higher profits. So new homes that spew carbon emissions into the atmosphere are now being sold in the neighborhood, ironically still under the Geos name.

But the net-zero Geos dream isn’t dead; it’s coming back as something new. Klebl has co-founded startup GeoSolar Technologies to create net-zero homes throughout Colorado and beyond. Geos resident Chang is the startup’s president.

GeoSolar retrofits existing homes (like a growing number of startups) and will build new ones with the same Geos technologies that harness renewable energy from the earth and sun. For retrofits, the company first conducts an energy audit of the home and makes a decarbonization plan that the homeowner can follow at their own pace, Chang says. The estimated costs currently range from $5,000 to $10,000 for the first tier of upgrades, principally weatherizing a home, to roughly $75,000 (after federal, local and utility incentives) for a complete makeover — including heat pumps, solar, CERV, EV charger, washer, dryer and home battery.

It’s still very early days for the company. GeoSolar has retrofitted two homes so far and has announced plans to build four more net-zero homes on land Klebl held on to in the Geos community.

To scale, the company plans to get groups of neighbors to decarbonize their homes at the same time. Retrofitting six or more buildings within a few blocks of each other could reduce costs for customers by an estimated 15 percent, Chang says. Using that strategy, ​“our goal is to be able to retrofit dozens of homes every month.”

Chang believes decarbonizing neighborhoods can create hotbeds of grassroots climate action. When you’re surrounded by climate solutions at home, he says, there’s a big cognitive dissonance when you look at the paucity of them at a policy level.

That’s something echoed by Geos resident Parker and his partner Ann Katzburg, both retired educators. They paid $735,000 for their Geos home, which they moved into last June. They love the neighborhood, which boasts a community garden and public fruit trees that anyone can pluck from, and organizes summer potlucks and weekly game nights. They and other residents have banded together to take climate action locally, including showing up to testify at city council meetings and door-knocking for a pro-climate candidate in an Arvada city election.

Chang notes, ​“We need people to have [net zero] be a part of their daily lives to really push their legislators to avert the worst climate outcomes.”