Minneapolis 'passive house' combines energy efficiency and contemporary design

Watching from their kitchen as their dog plays in the yard, Tim and Amy Eian point out how the south-facing orientation and floor-to-ceiling windows provide much of their northeast Minneapolis home's heat.

That's just one of the many features that make their home distinct, in addition to its sleek, modern design with oversized bright blue doors and gigantic windows.

To mark Earth Day (April 22), the Eians offered a tour of their home, the first new construction single-family home in Minneapolis to receive a passive house certification.

For years, Tim, a German native who heads the architecture firm TE Studio, had been designing homes with passive features, the core idea of which is to design spaces that are so well insulated they don't require a lot of energy to heat and cool.

When he and his wife had a chance to build their own abode, there was no question they would go all in with eco-friendly features.

"We've always wanted to build and raise our kids in a more energy-efficient home," said Amy.

Passive intentions

Much of the material for their home, built in 2020, is recycled or reclaimed or has a low impact on the environment.

"It's perfectly designed for our daily tasks and needs," Amy said of their 2,150-square-foot, four-bedroom, three-bath home. "We were trying to be conscious of not oversizing or having extra rooms. ... Every room in this house is used all the time. There's no wasted space here."

Appliances — from the water heater to the induction stove — are all electric rather than gas.

At times when their solar panels generate more than enough energy for the Eians, they sell that back to the grid. That covers the costs during times when they have to pull energy from the grid when there is no sun, Tim said.

About 60% of the heating in their home is sourced from the sun. And when the heater is running at full capacity, energy use is minimal, or the equivalent of two hairdryers running at the same time.

A heat exchanger pumps heat out of the outgoing air and adds it to the incoming air to minimize heat loss. Automatic window blinds further help control the temperature. And walls are insulated with recycled paper covered in borax to make it inflammable and airtight.

"You insulate yourself quite literally from the outside conditions," Tim said.

Passing the grade

Passive house standards were developed decades ago at the Passivhaus Institute in Germany and have been used worldwide. In the United States, standards are set by the nonprofit resource Passive House Institute U.S. To meet guidelines, factors such as energy efficiency and air tightness are measured.

While it's difficult to determine how many homes in Minnesota incorporate passive features, there are 11 certified single-family homes in Minnesota dating as far back as 2006 (the Das BioHaus in Bemidji), according to the Passive House Institute. Like the Eians, some of those houses are new, while others are remodeled century-old homes.

Paul Brazelton is among those homeowners who incorporated passive house features when taking on a major renovation of his 1935 Tudor-style home in south Minneapolis.

Ten years later, he's never looked back at pursuing passive house certification standards. Brazelton estimates that his electric bills have dropped by 60%, and that the family would probably save even more if not for their hybrid plug-in car.

It's always the perfect temperature inside the house, he said. Fresh air is pumped in (via a ventilator that cycles in filtered fresh air every few hours while pushing stale air out) and there are no cold, drafty areas, he added.

"My wife's hands would get really dry in the winter, and that's no longer the case because the house exchanges humidity," Brazelton said. "That was a weird, unexpected perk."

Minneapolis-St. Paul International Airport is a few miles away, so they're also enjoying new insulation and windows, which help control the temperature and dramatically reduce airplane noise.

"I've seen people doing things outside — mowing the lawn, snow blowing — and I don't hear anything," he said.

Affordability

A custom-built passive house could cost as much as 12% more to construct than one that does not comply with stringent energy-efficient standards. But in Tim's experience, the increase is closer to 3% to 5%.

Passive homes aren't just available for those in the single-family-home market, either.

One of the biggest passive home projects to take place in Minnesota was a 118-unit apartment building in northeast Minneapolis that opened in 2019.

The Hook & Ladder project was the first-of-its-kind multifamily construction project in the state. The building uses approximately 40% less energy than a complex of comparable size, said Kim Bretheim of LHB Architects in Minneapolis, which led the Hook & Ladder design team.

Although it was 15% more to construct the building, he said, the energy savings dramatically reduced operating costs, making it cheaper in the long run.

"This all helps from both a 'green' environmental perspective as well as from a housing stability perspective by both reducing energy demand and the unpredictability associated with variable energy costs," Bretheim said.

The interest in passive features shows no signs of slowing down, and the heightened curiosity has prompted the resource group Passive House Minnesota to host a home tour once a year in which the Eians and other families with passive homes roll out the welcome mat. (Upcoming tour dates have yet to be announced. For more information, visit passivehouseminnesota.org/)

Tim also finds himself fielding hundreds of calls a year from people who want to incorporate passive features into their remodels or new homes. He said many are looking for ways to combat climate change as well as lowering their energy bills.

"That pendulum is already starting to swing," Tim said.