The Pasive House - How it Works
Efficiency improves comfort
The Passive House is the world leading standard in energy-efficient construction: A Passive House requires as
little as 10 percent of the energy used by typical central European buildings – meaning an energy savings of up to
90 percent. Owners of Passive Houses are barely concerned with increasing energy prices.
Passive Houses require less than 15 kWh/(m²yr) for heating or cooling (relating to the living
The heating/cooling load is limited to a maximum of 10 W/m2
Primary energy use may not exceed 120 kWh/(m²a).
Passive Houses must be airtight with air change rates being limited to n50 = 0.6/h.
In warmer climates and/or during summer months, excessive temperatures may not occur more than 10 % of
The Passive House is a sustainable construction concept that provides for affordable, high-quality buildings as
well as comfortable, healthy living conditions. And its principles are quite easy to understand:
As newer buildings are increasingly airtight, ventilation through joints and cracks alone is not
sufficient to provide for fresh indoor air. Opening the windows as recommended won’t do the job either.
Fresh air is not merely a matter of comfort but a necessity for healthy living. Ventilation systems are
therefore the key technology for all future residential buildings and retrofits.
Even though ventilation systems do require an extra investment to begin with they will end up saving
considerable amounts of energy costs, provided that they are highly efficient systems. Passive House
quality ventilation systems will reduce the operating costs of any building.
This is where the Passive House concept comes in: As large amounts of fresh outdoor air need to be
supplied to the building anyway, why not use this air for heating? - Without any extra amounts of air,
without any recirculation of air, without any inconvenient noise or drafts? This way the ventilation
system pays off twice.
This “supply air heating” concept only works in extrtemely well insulated buildings – that is in
Passive Houses. In expert terms: The transmission heating load must be less than 10 W/m² to make sure
that the required heat can be provided by the supply air.