Passive House guide


Defined quality criteria The internationally applicable final definition of a building standard is unique so the end customer can be much more certain to really obtain the demanded and requested increased comfort.

Annual heat demand       (AHD)
max. 15 kWh/m²a The annual heat demand (AHD), also called energy performance indicator (EPI) must not exceed 15 kWh/m²a, as calculated according to the PHPP (Passive House Planning Package). This roughly corresponds to a maximum of 10 kWh/m²a, as calculated according to OIB (Austrian Institute of Construction Engineering – Guideline 6), but may require an AHD of 8 kWh/m²a at most according to OIB, if overall circumstances are unfavourable.
Heat load max. 10 W/m² If the building is to be heated only via the comfort ventilation system, the heat load is limited to 10 W/m² as well.
End energy demand (EED) max. 42 kWh/m²a End energy demand takes into account the annual heat demand, hot water demand, auxiliary power, ventilation power and household power. In total, the end energy demand in a passive house may not exceed 42 kWh/m²a, as calculated according to PHPP (Passive House  Planning  Package).
Primary energy demand (PED) max. 120 kWh/m²a

In order to ensure environmentally compatible coverage of energy consumption (including household power which alone accounts for half of total consumption) maximum primary energy consumption is limited to 120 kWh/m²a to save energy resources. The primary energy demand for passive houses is calculated by using the primary energy indicator according to PHPP.


Explanation of primary energy indicator PHPP

The primary energy indicator PHPP describes the total energy demand for operating buildings and is contingent on the following factors:
  • Energy demand (useful energy)
  • Efficiency of technical systems used
  • Primary energy factor (conversion factor) of energy sources used (considering upstream process chains such as electricity generation in power plants)


The primary energy indicatorPHPPtakes into account the demand for the below energy applications:
  • Heating
  • Hot water preparation
  • Auxiliary power demand of heat supply, solar and ventilation systems
  • Household electricity
  • (Cooling and dehumidification in office buildings and other climate zones, if required)


The balancing limit therefore deviates from the balancing limit specified in OIB Guideline 6, which does not include household electricity demand.

If the method of identification is PHPP, the primary energy indicator is calculated based on the primary energy factors from PHPP. These factors deviate from the factors of EN 15603 which are used in this version of the catalogue of criteria in case of identification in accordance with OIB Guideline 6.

Building pressure test      n50 -value max. 0,6 h-1 The building envelope must be air-tight and windproof. Compliance with this criterion is verified in a building pressure test (also called blower door test), it must not exceed a value of n50 of 0,6 h-1.

Specific reference values of individual building parts and components

For reaching these overall targets, specific reference values must be fulfilled by individual building parts or components, including reference values such as:

  • U-values of all building parts of large-volume structures ≤ 0.15 W/m²K, of single-family homes ≤ 0.10 W/m²K
  • Glazing with Ug-values ≤ 0.7 W/m²K and a g-value ≥ 50%
  • Window frames including glazing with Uw-value ≤ 0.8 W/m²K according to DIN EN 10077
  • Design without thermal bridges related to external dimension
  • Consistency of airtight level
  • Consistency of windproof level
  • Comfort ventilation system including highly efficient heat recovery ≥ 75% (acc. to PHI certificate) at low power consumption (≤ 0.4 Wh/m³)
  • Sound level exposure through ventilation system must be very low (< 25 dBa)
  • Lowest heat losses in domestic hot water production and distribution
  • Highly efficient power-saving household appliances
  • Calculation using PHPP (Passive House Planning Package) acc. to Passivhaus Institut Darmstadt, Dr. Wolfgang Feist

However, it is not enough to just combine individual components. What is important is that the overall concept works well.

PHI-certified passive house components

In order to make sure that the individual components actually can be used for the passive house, we recommend to use only PHI-certified passive house components, if possible. For a list of all currently available components go to

Why certified products?

The passive house stands out by high-quality components: Super-insulating window frames, highly efficient ventilation units, connection details without thermal bridges, glazing allowing solar net gains, ...

But planners often have difficulties in assessing the energy efficiency of building parts and the parameters that should be used: Parameters available from standardisation often are not realistic or not sufficiently precise; reliable planning frequently cannot be guaranteed by using manufacturers' data only.

The Passivhaus Institut is an independent centre to test and certify products for their suitability in passive houses. Products awarded the certificate "Component suitable for passive houses" have been tested under uniform criteria, their parameters are comparable, and they are of excellent energetic quality. Using them makes it much easier for planners to do their work and significantly contributes to warrant the proper function of the passive house under construction. Meanwhile, PHI-certified passive house components have become available all around the globe.
Certificate "Quality- tested passive house” 

To be on the safe side, we recommend to have your passive house certified by external testers according to the requirements of Passivhaus Institut Darmstadt, Dr. Wolfgang Feist. The following companies and institutes in Austria are authorised to issue a passive house certificate:

Certificate          „klima:aktiv haus gold“

Apart from the requirements for being granted the certificate “Quality-tested passive house”, the building has to fulfil yet other ecological criteria broken down into assessment categories to obtain the certificate „klima:aktiv haus gold“.



  • Planning and execution (infrastructure, barrier-free accessibility, avoidance of thermal bridges, air tightness)
  • Energy and supply (useful, end and primary energy demand, CO2 emissions, water demand)
  • Building materials and construction (avoiding questionable building materials, ecologically optimised building materials, ecologically optimised building production)
  • Indoor air quality and comfort (ventilation, indoor pollutants, thermal comfort)


Passive solar energy use Passive houses oriented to the South are solar houses at the same time. Following exploitation of the efficiency potentials, the passive use of solar radiation flowing through the windows designed for sufficient lighting covers approximately 40% of the remaining heat loss. For this purpose, passive house windows through which more solar heat can flow in than gets lost are used. Orientation to the South of the main lighting areas and freedom from shading are favourable features. However, orientation to the South is no prerequisite for reaching the passive house standard.
Comfort ventilation with efficient heat recovery Comfort ventilation systems supply passive houses constantly with fresh air, introducing exactly the quantity that is needed for good-quality indoor air, roughly 30 m3/h and person. By using a highly efficient heat exchanger heat is transferred from the exhaust air to the fresh air flowing in, without blending the air flows. On particularly cold days the intake air is heated additionally. Fresh air can also be preheated via an underground or brine heat exchanger, further reducing the need for reheating.
Electricity efficiency

Using efficient household appliances, hot water connections for washing machines and dishwashers, dryers and energy saving bulbs saves household electricity consumption in passive houses by more than 50% compared to average structures without reducing comfort. All building services have to be highly efficient. The ventilation system, for instance, is running on particularly efficient DC motors. The price of efficient household and office devices often is not higher than of average units. Usually they pay off as power consumption is reduced.

Renewable energy sources

The lower remaining energy demand of passive houses can be covered, ideally at 100%, by renewable energy sources. A cost-optimised thermal solar plant may cover approx. 40-60% of the complete low-temperature heat demand of a passive house, for which in most cases 5 – 8 m² per residential unit should suffice for hot water and heating due to the low remaining energy demand. For increasing the share of solar power generation it makes sense to install a rooftop and/or facade-integrated photovoltaic system for the passive house.

The passive house standard is the prerequisite to implement cost-efficient zero and plus-energy houses.