Earlier this year, a "passive house" in Los Angeles went viral.
In the fallout of the Pacific Palisades wildfire, the simple residence remained relatively unscathed, still standing amid the rubble. Designed by Santa Monica-based Chasen Architecture, the home was “very lucky,” architect Greg Chasen wrote in a post on X, formerly Twitter. But some of its design moves also helped improve its odds.
“Passive house is not focused on fire mitigation or fire safety,” explained Lindsay Schack, co-founder of the Bozeman, Montana-headquartered firm Love Schack and a certified passive house consultant. “But if you marry fire safety principles with it, your house will be the one that’s standing and not be riddled with smoke damage on the inside when a smoke event comes through your neighborhood.”
The design methodology traces its roots to 1980s Germany and remains concentrated throughout Europe, which boasts more than 139 million square feet of certified passive house structures. The United States, which didn’t get its first certified passive house until 2003, lags that figure quite a bit, although interest in the building method is steadily increasing as homeowners look to boost the efficiency and resilience of their investment. Currently, Phius, a Chicago-headquartered nonprofit focused on decarbonizing the building industry, has fully certified 6.9 million square feet of passive projects across the U.S. But there are other U.S. certification services, so that total passive square footage could be even higher.
There are energy savings and health benefits
Basically, a passive house is a highly efficient building that prioritizes interior comfort and air quality, while putting the structure well on the way to net-zero energy use. It all comes down to airtightness, which keeps conditioned air inside, and continuous insulation. These characteristics give the homes three main selling points, explained James Ortega, certification program director at Phius, a Chicago-headquartered nonprofit focused on decarbonizing the building industry.
“First and foremost, these homes are really, really comfortable,” said Ortega, also a registered architect. Thanks to continuous insulation, high-performance windows and designs that prevent inside air from leaking out through the walls, passive homes are cool during the summer and cozy in the winter. Those barriers also block outside noise, keeping passive homes quiet, even in loud neighborhoods.
Although the structures are airtight, a balanced ventilation system ensures living areas have a constant supply of fresh air, which makes the “air quality substantially better than normal construction,” Ortega noted. In the event of a disaster that might compromise outdoor air quality — like a wildfire — the building method keeps ash and fumes outside the home.
That barrier can positively affect the health of passive house occupants, said John Loercher, a certified passive house consultant and owner of Northeast Project. After clients live in their passive house, they end up reflecting on their home’s “resilience and health qualities."
“I’m asthmatic and there’s a definite benefit to me there, but I’ve also met … immunocompromised people that are actually seeking out this higher quality of interior living," Loercher added.
Those efficient design strategies also mean that passive house homeowners see a long-term benefit when it comes to their electric bills.
“At the end of the day, you’re going to save a lot of energy on your annual heating and cooling bills by going this route,” Ortega said. Some passive houses equipped with solar arrays can even generate excess energy that gets fed back into the grid.
What people get wrong about passive homes
As the passive house movement expands in the U.S., the methodology still faces misconceptions. Ortega sometimes sees people confuse passive houses, which optimize heating and cooling, with passive solar homes, a building strategy popular in the 1970s that maximized south-facing windows.
Another point of confusion: Despite the name, almost any kind of building could be a passive house. “We know a lot of these concepts are applicable to buildings of all sizes, so we see plenty of multifamily and nonresidential,” Ortega noted.
Some people interested in passive houses also have questions about the windows, wondering if the structure is airtight, can I still open my windows? Yes, Ortega assured, you can have operable windows. “But when your windows are closed, we don’t want the building to have infiltration, which is a major source of moisture and draftiness.”
Moisture itself can be a point of concern for potential passive house residents. “One major misconception of the early days was, ‘if I make my building too airtight, won’t my walls not be able to breathe?’” Ortega recounted. And if walls can’t breathe, won’t mold grow inside?
“That’s really not something we’ve seen on a project if you designed your vapor and air barrier controls properly,” Ortega said. So no, no mold.
But concerns about higher upfront costs are trickier to navigate. The hard costs of a passive house project, from better windows to more insulation, can mean that a passive project costs more than a nonpassive single-family build, Ortega said. Scope can lower that threshold — passive multifamily projects have a smaller cost increase than single-family dwellings — along with experienced project teams. Architects and builders with at least one passive project under their belts can nimbly navigate passive building strategies and help their clients drive costs down.
Potential clients can also work with their design teams to investigate government incentives, rebates and tax credits that could help defray the cost of a passive house project.
“A lot of states have great incentives for passive house,” Loercher explained. “So, the way that I see it, is if you’re in a state like New York or Massachusetts or Pennsylvania … there are incentives in place that help offset that cost to get a better product.”
Even in an uncertain economic environment, decarbonization nonprofit Phius is seeing an “uptake in terms of projects being registered,” Ortega said. With construction costs going up regardless, “the passive building has a better [return on investment] in the long term because you’re going to be saving money 10, 20, 30 years down the road,” Ortega said.
Ortega is seeing architects and designers interested in elevating sustainable building practices lean into that argument. “We can’t control the cost of lumber, we can’t control the cost of labor,” he said, “but what we can control is how much energy this building is going to use, or we can control people’s comfort and give them something that they’re going to be happy to pay for.”