The number that defines the standard
This is the core Passivhaus criterion, calculated over the treated floor area. It comes out of a heat balance: transmission and ventilation losses, minus the solar and internal heat gains the building already receives. Meet it and the house needs about five to ten times less heating energy than a conventional build of the same size.
Passivhaus vs a conventional house
The 15 kWh/m² limit and the 10 W/m² peak load are what set the standard apart. Both sit far below normal construction.
Heating energy per year. A Passive House uses roughly 75–90% less than a standard home, which is why its peak load falls from 50–100 W/m² to just 10.
The full set of criteria
| Criterion | Passivhaus limit | Conventional |
|---|---|---|
| Heating demand | ≤ 15 kWh/m²·yr | 75–150 |
| Peak heating load | ≤ 10 W/m² | 50–100 |
| Airtightness | ≤ 0.6 ACH₅₀ | 3–10 |
| Heat recovery | ≥ 75% | none typical |
| Wall U-value | ≤ 0.15 W/m²K | 0.3–0.5 |
| Window U-value | ≤ 0.80 W/m²K | 1.4–2.8 |
Airtightness is verified with a blower-door test. The heat recovery ventilation is what makes the low demand possible: it reclaims 75–85% of the warmth in outgoing air instead of throwing it away.
Common questions
What is the Passivhaus heating demand limit?
A certified Passive House must use no more than 15 kWh per square metre of floor area per year for heating. That is the headline criterion, alongside a peak heating load of 10 W/m2 and airtightness of 0.6 air changes per hour at 50 Pa.
How much less energy is that than a normal house?
Roughly 75 to 90% less for heating and cooling. A conventional home often needs 75 to 150 kWh/m2 per year; a Passive House stays at or under 15. The peak load drops from 50 to 100 W/m2 down to 10.
Does a Passive House still need a heating system?
Yes, but a small one. Because peak demand is so low, a 1 to 2 kW heater, a modest heat pump or a small gas boiler is enough where a conventional house would need 5 to 10 kW or more.
