Passive House Design
Homes so efficient, a TV could nearly heat them.
Passive house is the world's most rigorous building energy standard — superinsulation, verified airtightness, triple-glazed windows, and heat-recovery ventilation working as one system. LEAP has practiced and written about this discipline for years; it is the deep end of the building science that informs everything we design.
Comfort is the point. Efficiency is the byproduct.
People come to passive house for the energy numbers and stay for how the buildings feel: air that is always fresh, surfaces that are never cold, silence where mechanical noise used to live, and temperatures that barely move through a nor'easter. The physics that cuts heating demand by ninety percent is the same physics that produces the most comfortable rooms you have ever occupied.
We apply passive house principles across our portfolio — from full-standard projects to renovations that borrow its detailing — and we hold every design against the 2030 Challenge carbon targets. This page distills the thinking we've published on insulation, air sealing, windows, ventilation, and measured performance into one place.
The System
Six principles, one building.
Passive house works because its elements reinforce each other — remove one and the physics unravels. Here is the whole machine.
Superinsulation
Passive house walls carry two to three times the insulation of code construction, installed continuously so framing never short-circuits the thermal layer. The building wears a proper winter coat — and keeps its summer shade — every hour of every year, with no moving parts to fail.
Airtightness — and proper breathing
A passive house is built astonishingly tight — verified by blower-door test at a fraction of code leakage — and then ventilated deliberately. The old saying that a house must breathe was always half right: buildings need controlled fresh air through dedicated ventilation, not accidental drafts through gaps in the framing. Tight plus ventilated beats leaky every time, for comfort, durability, and air quality alike.
High-performance windows
Triple glazing, insulated frames, and airtight installation turn the envelope's weakest points into assets. Passive house windows stay warm to the touch in January — which eliminates the cold-radiating surfaces and convection drafts that make conventional rooms feel chilly even at seventy degrees. Orientation and shading are tuned so the same glass that harvests winter sun refuses summer overheating.
Heat-recovery ventilation
A heat-recovery ventilator supplies continuous filtered fresh air while capturing most of the warmth from outgoing stale air. Every room gets fresh air all the time; almost no heat is lost obtaining it. It is the lungs of the building — quiet, efficient, and running around the clock.
Minimal heating demand
Do the first four jobs well and the heating system nearly disappears. A certified passive house needs roughly a tenth of a conventional home's heating energy — famously, on the coldest design day, something close to the heat of a large TV and its audience per room. In practice that means tiny heat pumps, no radiators under every window, and mechanical budgets reallocated to architecture.
Verified performance
Passive house is a measured standard, not a marketing adjective: energy modeling during design, blower-door testing during construction, commissioning at completion. The numbers are the promise — and the buildings deliver them decade after decade.
Frequently asked questions
What is a passive house?
A passive house is a building designed and verified to an ultra-low-energy standard: superinsulated, extremely airtight, ventilated with heat recovery, and glazed with high-performance windows — so it needs about a tenth of a conventional building's heating energy. The name refers to the approach, not the style: any architecture, traditional or modern, can be built to the standard.
Does a passive house cost more to build?
Typically a modest premium over comparable quality conventional construction — commonly cited in the five-to-ten percent range — much of it recovered immediately through smaller mechanical systems and then permanently through utility bills. Incentives from NYSERDA and federal programs narrow the gap further. Over ownership, it is the cheaper house.
Doesn't a house need to breathe?
It needs to breathe deliberately, not accidentally. Random leakage through walls causes drafts, moisture damage, and energy loss while delivering fresh air unevenly at best. A passive house pairs an airtight envelope with continuous heat-recovery ventilation — every room receives filtered fresh air constantly, with the warmth recovered. Occupants report better air than any leaky house ever provided.
Can a renovation reach passive house performance?
Deep-energy retrofits can approach or meet the EnerPHit retrofit standard, and even partial application — exterior insulation during residing, airtightness during a gut, window upgrades — captures a large share of the benefit. We fold passive house detailing into whatever scope a renovation already has.
Do passive houses overheat in summer?
Not when designed properly. The same envelope that holds heat in January holds it out in July, and shading is calculated so high summer sun is rejected while low winter sun is welcomed. Small cooling loads are handled by the same right-sized heat pumps — passive houses ride through heat waves more comfortably than conventional homes, not less.
Is passive house certification required to get the benefits?
No. Certification adds verification rigor and resale documentation, and some clients want it. Others take the detailing and the testing without the plaque. We design to the physics either way and will lay out the certification decision honestly — it is a value judgment, not a prerequisite for comfort.
How efficient could your project be?
Bring us your site, your house, or your idea — we'll map the realistic path from code-minimum to passive house, with honest numbers at every step.