Passive House Frequently Asked Questions

Passive House is a building standard for comfortable, healthy buildings that use very little energy. It starts with the enclosure, insulated and airtight like a thermos, with fresh air brought in through ventilation with heat recovery. The Passive House Institute (PHI) puts the result at heating and cooling demand cut by as much as 90%.

It’s performance-based, not prescriptive: the standard sets the results, and the design team chooses how to get there. More: What is Passive House?

Steady, comfortable temperatures all year, with no drafts. Filtered fresh air all the time, with stale air and indoor pollutants carried out. Quiet inside. Low energy bills that move less when energy prices jump. And resilience: an insulated, airtight building holds its temperature through a power outage far longer than a conventional one, so people can often shelter in place.

Everyone benefits, and people with the fewest resources benefit most. In many US cities, low-income neighborhoods are hotter than wealthier ones, see more air pollution, and spend a larger share of income on energy. Passive House answers all three: steadier indoor temperatures, filtered air, and lower bills. Our report Safe at Home sets out the evidence.

All of them, from arctic to hot and humid. PHI’s criteria are set for each climate zone, and each project’s energy model uses its own climate data. See buildings in each climate: Case studies.

PHI’s process is focused on ongoing research, high-quality outcomes, and the handful of building principles that drive them, transforming industry and culture. It is the gold standard.

Phius took the PHI methodology and made it more accommodating to American industry, resulting in less clarity of purpose and allowing lower-performing outcomes.

Yes. A building’s emissions come from the energy it uses in operation and from the energy embodied in its materials and construction. Passive House is the most effective way to cut the first: it cuts heating and cooling demand at the source, and a building that needs so little energy is easy to run on renewables.

PHI certification doesn’t set a limit on embodied carbon. But the Passive House methodology can, and should, support buildings with low or even negative embodied carbon, and many of the same choices serve both: compact forms, durable assemblies, and bio-based insulation.

Usually a small one, and it shrinks with experience. In 16 multifamily projects that Steven Winter Associates consulted on in 2020–21, first costs ran 1% to 8% over baseline, the highest for teams new to Passive House. In Pennsylvania’s tax-credit housing, the premium fell from 5.8% in the first year to 1.6% in the second and –3.3% in the third.

More: Is Cost the Barrier to Passive House Performance?

Yes. Six New York City multifamily Passive House buildings used 32% to 58% less energy than conventional buildings built after 2003, and their total energy costs were 28% to 68% lower (Multifamily Passive House: Connecting Performance to Financing, 2021).

To get the most from it, invest in operations: trained maintenance staff and regular filter changes. The airtight, well-insulated enclosure also lowers the risk of moisture damage and mold.

Increasingly. Lower operating costs raise net operating income, and lenders can count energy savings toward debt. Carbon laws such as New York City’s Local Law 97 penalize buildings over their limits; the six Passive House buildings in the same study would meet the city’s 2030 limits.

Investors also weigh environmental performance. GRESB, the Global Real Estate Sustainability Benchmark, lists Passive House and EnerPHit among the building certifications it recognizes (GRESB reference guide).

Yes, and many are written for PHI certification: utilities, state housing finance agencies, and lenders reward it. They’re set out, program by program, on Building Financial Incentives.

As with any new way of building, the first project is the steepest. Training helps most, and the design, development, and construction leads should each have some. PHN offers CPHD/C courses for designers and consultants, CPHT courses for builders and the trades, and continuing education. To find people who’ve done it: Find a professional.

You can build without certifying, but certification is how you know it performs. A PHI-accredited Certifier checks the design, the energy model, and the evidence from construction, including the airtightness test.

Certification also opens doors: codes in six states and the District of Columbia accept it as a way to comply, and utilities, housing finance agencies, and lenders reward it. More: Certification, Codes, and Building Financial Incentives.

A limit. LEED credits energy-efficiency measures but doesn’t cap how much energy a building uses; Passive House does, and checks it through the energy model and testing. The two work together.

A Building Certifier, at the start of planning. Bring one in early, so the design stage review is done before construction contracts are awarded, while changes are still cheap. The Certifiers working in the US are listed on our Certification page; contact a few and compare.

No. It works for any building type and size. Certified buildings include hospitals, schools, dormitories, assisted living, a car dealership, a textile factory, and a dentist’s office. See some: Case studies.

Any construction type and cladding can work, wood frame included. The standard sets the performance, not the materials.

Yes. EnerPHit is PHI’s standard for retrofits, done all at once or step by step as parts of the building reach the end of their life. Its criteria are on our Certification page.

Yes, windows open, and natural ventilation is welcome in mild weather. But it can’t be relied on all year, so a Passive House has mechanical ventilation with heat recovery, supplying filtered fresh air to every occupied room, usually around the clock.

No, but it’s encouraged: an all-electric building is ready for a renewable grid and avoids replacing fossil-fuel equipment later.

No system is required. With loads this small, heat pumps (air, water, or ground source) are the common choice, often heating and cooling from one system.

Base it on data. Track utility use, with tenants’ agreement. If the building runs as designed and tenants pay for heating and cooling, those bills should drop markedly. The savings are in heating and cooling; plug loads like computers and appliances are up to each household.

Compare its annual energy use with the energy model’s prediction. Sensors, from a few spot readings to a full building management system, can track energy and indoor air quality in more detail. And ask the people who use it: they should find it comfortable and draft-free, with fresh air, and quiet.

Yes. The ventilation and its filters, the airtight enclosure, and the heat pumps all need informed care. Courses for owners and operators are in our continuing education.