Passive house

Under a passive house means a building that does not require classical building heating due to its good thermal insulation in general.

  • 2.2.1 constant internal temperature
  • 2.2.2 Air Quality
  • 2.3.1 additional costs of passive house
  • 2.3.2 reduced costs Passive House
  • 2.3.3 maintenance costs
  • 2.3.4 promotion Germany
  • Austria
  • 3.1 PHPP standard of the Passive House Institute (Quality Approved Passive House )
  • 3.2 Germany: Energy Standard
  • 3.3 Austria: Class A Energy Performance Certificate, klima: aktiv building standard
  • 3.4 Switzerland: Minergie P


The Passive House may, according to the certification criteria of the Passive House Institute in Darmstadt a heating requirement of 15 kWh not exceed (energy content of about 1.5 liters of fuel oil ) per square meter in a year. The maximum heating load is 10 W / m² and must be introduced via the supply air in winter to unfavorable days. Furthermore, a passive house by limits within the range of primary energy demand of 120 kWh / ( m² · a ), the air tightness and the minimum efficiency is defined.

The houses are "passive " because the vast majority of the heat demand from "passive" sources will be covered, such as sunlight and heat from people and technical equipment. The result is a positive perception of space, coupled with low energy consumption. Here, the passive house is not new construction, but a construction standard, which has special requirements with respect to defining architecture, technology and ecology and not restricted to a particular type of building. It is also possible by alterations and renovations, to achieve this standard.

Passive house construction

Principle of operation

A typical passive house features the design features shown in the figure. Deviations are possible at any point, as long as get the principle remains (functional default).

When passive house an above-average recovery of the radiation heat of residents and household appliances is achieved by special insulation in walls, windows and roof. A sophisticated ventilation system also reduces heat loss and regulates the supply of fresh air for the residents. The fresh air is often pre-heated by a geothermal heat exchanger supplied to the building. Important components are also extremely good air tightness, as well as a special form of the building. The building heating system at extremely low temperatures by common heating systems such as district heating, gas or oil heating, wood burning stove or a solar technology system characterizes the boundary region with highly insulated conventional building technologies.

In general, the auxiliary heating is carried out at the passive house via electric heater or an electrically operated air-air heat pump heating via the ventilation system. Are also common ( especially in the bathroom ) tiles electric heaters. Passive houses have, therefore, in spite of their energy efficiency is usually a higher consumption of electrical energy than conventionally heated homes.

Thermal insulation

Focus on energy conservation in passive house is the reduction of energy losses by transmission and ventilation. This is achieved by good thermal insulation of all surrounding surfaces (roof, basement walls, foundations, windows), a largely tight building envelope and a controlled ventilation system with heat recovery from the exhaust air. Thermal bridges and leaks are to be avoided (even at the terminals ).

The windows are mostly triple-glazed at Central European passive houses, have selective layers to each disc space and are equipped with argon gas (rare krypton ) filled. Although such windows have a poorer thermal insulation value as well insulated walls, a non- shadowed as possible in winter south window of this quality even in winter by solar energy gains has a positive energy balance. Meanwhile, there are special window designs for passive houses, for example, with two consecutive casements, which still guarantee higher solar gains and the best possible heat protection.

If possible, narrow frame to maximize the relative proportion of the glass surfaces, thereby optimizing the energy input, including because the U-value of triple glazing with about 0.5 to 0.7 is significantly better than that of the frame. Window designers have always strived to build narrow frame to have a high glass area ratio also with small windows. The nature of the involvement of the window in the wall cross-section ( design and installation ) contributes significantly to the insulation.


The building envelopes, especially of new buildings are generally virtually airtight. As a result, adequate natural ventilation is not provided with the windows closed. Therefore ventilation systems are now often, and not only in passive houses built, which provide for the removal of stale air and water vapor, and thus a pleasant room climate. To limit the heat vent, passive houses need a controlled living space ventilation, usually with heat recovery. This provides the necessary air exchange and reduces energy loss through window ventilation. About every 1 to 4 hours is exchanged in the house all the air. For this required low air flow rates of air movement, drafts or noise is not noticeable. At higher air exchange rates and narrow channels to flow noise may be audible. The fresh, filtered and preheated air is supplied to the living rooms and bedrooms, from where it passes through overcurrent openings ( for example, in or above the doors or by means of undercut door leaves) in the corridors and is sucked back into kitchens, bathrooms and toilets. From there, the air passes through channels to the heat exchanger and, finally, as exhaust air to the outside.

The heart of the ventilation system is the heat recovery with a heat exchanger, usually a counterflow heat exchanger. The heat from the exhaust air may be recovered there from 80 to 95% of the supply air, without a mixing of the air takes place. In normal operation, such a system does without heating function for a single family home to about 40 watts of power. There are devices with a rotary heat exchanger that can also recover a portion of the humidity. The air filter of Gegenstromwärmeübertragers can also be exchanged for a pollen air filter. Also leaves you with ionisation be improved by the installation of a ionization air quality and reduce pollutants.


A large part of the heating requirement is, that is, the heat given off by people and equipment, as well as covered in passive houses of internal gains from solar gains during the heat via the windows.

The still existing residual heat demand can be provided by any sources ( eg, gas heating, district heating, heat pump, electric building heating, solar thermal system, pellet stove, or by an oil fired central heating). The Passive House criteria of the Passive House Institute in Darmstadt is a theoretical heating demand of 15 kWh per square meter of heated living space and year. This corresponds to an energy demand in the space of about 1.5 liters of fuel oil, against losses resulting from the production and transport in the building. Such a low heating demand can be covered by a heating of the supply air to the ventilation system required are compact and involvement of internal heat sources, such as the heat release of the residents. Regularly, a heating of the supply air cover only a small heat load of about 10-20 W per m². This is mainly due to the low heat capacity of the medium and the air, depending on the heat source, more or less high and limited temperature difference between the supply air behind the surface and the ambient air temperature. Larger passive houses with low occupancy density are usually as conventional building via static heating surfaces, heated just with smaller size. However, the need is also essential from the user's behavior depends. Important factors are, for example, the desired room temperature, shading the windows and the ventilation behavior ( airing or window permanently in tilt ). In extreme cases, the actual heat demand may be at a multiple of the optimal possible.

For smaller passive houses often so-called compact devices are used, in which a controlled living space ventilation, hot water, a mini - heat pump and electric auxiliary heater are integrated and do not represent classical building heating. On the other hand, provide "conventional" systems of heat generators and separate ventilation not only cost and efficiency benefits: a device fault or due to technical progress components of the system can be renewed; with choice of single devices the particular conditions of a construction project can be considered adequate.

Sense of living

Constant internal temperature

The essential and special property of a passive house is the constant internal temperature. This applies both seen through the year and a day as well as for individual rooms. The internal temperature changes only very slowly - when heating is switched off it sinks in the passive house by less than 0.5 K per day ( in winter when there is no sun ). All walls and floors have the same temperature, the same applies to the cellar, if it is within the thermal envelope. There are no " cold" exterior walls or floors, mold is thereby excluded. In summer, the thermal insulation and a possibly existing geothermal heat exchanger ensure that the building remains cool and no air conditioning (at least in Central Europe) required care. This is also true for office and school building in passive house standard ( Source: Working group volumes summer climate and Passive House schools).

However, the constant internal temperature is not felt by all people as comfortable. Separate temperature control for example the bedroom ( slightly cooler ) or the bath ( a bit warmer ) is very often desirable to passive house but not, or only with additional effort ( Bad example: additional electrical heating tile ) can be achieved.

Air Quality

The controlled ventilation of a passive house makes use of air filters for better air quality of indoor air compared with the outside air. You can take over the function of heating with electric heating coils or air -to-air heat pump when the maximum heating load remains in all cases during the lifetime of the house less than 10 W / m². A rapid heating is not possible with a sole heating via controlled ventilation because of the small reasons of comfort air exchange rate of 0.4 / h to 1.0 / h. Additional ventilation is always possible, but basically not necessary.

The in some cases, reported lower relative humidity, especially in cold periods in winter can be raised by reducing the air exchange rate, but what counteracts the heating function when the heating is only on fresh air. It also devices with an integrated moisture recovery are offered.


Experience shows that the new building are about 5 to 15 % more expensive than a conventionally built house after the currently valid energy standard Energy Saving Ordinance. During the renovation of old buildings, these additional costs moving experience has shown that between 12% and 18%. The cost of the ventilation system in a family house will be approximately 6000-10000 € (2007) readily implemented depending on the equipment.

The payback period can be more than ten years; it mainly depends on the unpredictable future energy price increases as well as the interest rate at which the investment is financed from. The basic savings in heating energy is compared to a conventional building according to the latest building standards around 75 %.

More costs for the Passive House

  • Particularly good thermal insulation ( material costs for the insulation material (by volume) )
  • Allowances for increased outside areas, possibly consuming connection work and detailed drawings.
  • Basically, the use of ventilation systems with heat recovery
  • Very good insulating windows with triple insulation glazing
  • Increased demands on the airtight building envelope
  • In some cases, increased expenditure for special solutions (eg for a cat flap )

Reduced costs for a passive house

  • Chimney flues often not necessary - thus a little more living space (0.5 m × 0.5 m = 0.25 m ) and no chimney sweep cost
  • Rarely radiator, wall or floor heating and its related technologies are needed
  • Heating or fuel storage room often not necessary
  • Most lower maintenance costs for hot water and heating system


Since heating usually as a powered heat pump is used, you have an increased demand for electricity in a passive house, but are no separate heating costs. With 1 kWh of electrical energy the heat pump from 1.3 to 3.7 kWh of heat transported to a higher temperature level. In addition, the applied electric energy may also be used as heat. Thus, there are 2.3 to 4.7 kWh of heat per kWh applied electrical energy. The performance rate is reported as a Coefficient Of Performance (COP ) in the plant descriptions. If the heat pump is used for hot water production, energy demand rises, as the heat pumps work less efficiently at higher temperatures required. The hot water through water heater also requires high-quality, expensive electrical energy. As often vents with electric heating elements and electrical Fliesentemperierungen be installed, increases in their use of the demand for electric "side power " clearly.

The maintenance costs for the building services is that of a normal house with additional ventilation. The ventilation (without electrical heating ) with about 40 watts average power consumed in about 350 kWh, plus the cost of filter replacement.



In Germany, passive houses are funded by a soft loan from the Kreditanstalt für reconstruction. There is in many states regional funding programs.


In Austria Passive houses with up to 10% of the construction costs will be funded. The State of Tyrol promotes passive houses in the course of housing subsidies with additional funding for energy- saving design with 14 points. Promoting height of a point is derived from the eligible residential area in m² x 8 €. Target, for example, a family of four with a maximum supported living area of ​​110 sqm, it follows the 110 × 8 = 880 € per point. With 14 points, the results in an additional funding of € 12,320 (as of June 2007).

The State of Vorarlberg promotes passive houses with a set of up to € 1,100 per square meter up to 150 m², ie a maximum of € 165,000, provided that the guidelines have been met ( income limits, floor plan, people). However, this promotion must have a term of approximately 30 years of extremely low interest rates and are not amortized value is guaranteed, so this also has a strong promoting effect for young families and the construction industry directly.


It is disputed whether the building technology in a passive house ( ventilation heat pump) is about the same price as a conventional house without ventilation ( heating heating). Increase the construction costs effectively. Around the amount the better insulation costs (windows, insulation ), according CEPHEUS by about 5 to 8% The CEPHEUS study came to the conclusion that the capitalized total cost over 30 years for a passive house were not higher than in a conventional building. The higher cost of capital from the first day are faced with the lower energy costs from the first day. Benefits are "below the line " the higher quality of living through the ventilation, the security against future energy price increases and better CO2 balance.


The added value of passive houses in terms of environmental protection and comfort is controversial. Low energy buildings with high solar fraction can reach an individually controllable indoor climate often even lower ongoing total cost of similar investment costs. By eliminating or reducing the use of additional insulation to their environmental performance improved.

Critical is sometimes argued that the financial comparisons were fined between passive house and conventional low-energy houses. The reasons for doing so is not limited to:

  • The comparative calculations regarding energy consumption are often based on outdated standards. It is usually ignored that today's standard homes, according to recent regulations ( for example, the German Energy Saving Ordinance ) are much better than they did at the turn of the millennium, as passive houses found increased public attention. Comparisons against KfW Efficiency houses accordance with current standards are rarely made.
  • Ventilation systems with heat recovery and very good thermal insulation (eg triple glazing ) are clearly no unique features of passive houses and more are also increasingly used in conventional construction.
  • Comparative calculations usually do not consider that the investment must often be financed for a new building to more than 70 %. The interest costs are thus not adequately taken into account in the comparison.
  • The higher material and thus energy demand in the manufacture and installation of thermal insulation must be from an environmental point of view amortized (see crop factor).
  • A passive house corresponds to the popular definition of " air conditioned " with the consequent problems: A pleasant room climate demands a very technical interpretation of the ventilation system. This must be carried out by specialist companies. This is true - as in fully air-conditioned office buildings - even for a reconfiguration in use change, for example, if a storage room to the bathroom will be expanded. In conventional buildings, this would only a modified "airs behavior " is required.

Passive House standards

Based on the passive house energy standards have been developed. Here, one can start from a benchmark of the area-related annual heating demand of 15 kWh / ( m² · a ) today. At this value, the most significant savings are achieved in comparison to conventional housing at Heizstoffverbrauch: This corresponds to a consumption of fuel oil equivalent of about 1.5 liters of heating oil per square meter per year.

Certifications based on energy standards have been defined by the private sector and government agencies on a statutory or standards - based. The former serve primarily as a quality assurance measure in terms of a hedge in the construction industry and for the customer, temptation also to implement the objectives of the Kyoto Protocol ( UNFCCC United Nations UNFCCC Protocol Conference Kyoto 1997) and for support measures or moneys.

PHPP standard of the Passive House Institute (Quality Approved Passive House )

From the Passive House Institute in Darmstadt, the concept Passive House Planning Package (PHPP ) is being developed. This includes the following basic conditions are defined:

  • Specific space heat demand max. 15 kWh / (m² · a) or heating load max. 10 W / m
  • Pressure test air exchange n50 max. 0.6 h -1
  • Energy characteristic value of the total primary energy max. 120 kWh / ( m² · a ) including household electricity

For additional non-residential buildings shall:

  • Energy characteristic of useful cooling max. 15 kWh / ( m² · a )
  • And any special conditions from cool - temperate climate of Europe different site conditions and special cases of the use of the building

The PHPP - concept consists of a substantial criteria catalog. Based on this framework, the Institute certified building with the label Quality Approved PASSIVHAUS Dr. Wolfgang Feist.

The Passive House Institute is a research center founded by Wolfgang Feist and one of the leading institutions in the field of Passivhausbauens. It was instrumental in the development of the German energy standard norms; on the PHPP standard is based and the Austrian government klima: aktiv standard.

Germany: Energy Standard

The term describes according to German standard position an energy standard for buildings.

The precise definition is:

" A passive house is a building in which thermal comfort (ISO 7730) can be ensured solely by post-heating of the fresh air flow, the proper air quality (DIN 1946) is required -. , Without this additional use of air recirculation"

The precise requirements for a passive house are described in the Passive House energy standard. This is a further development of the standard for low-energy houses. An inspection for compliance with the standards does not exist in Germany.

Austria: Class A Energy Performance Certificate, klima: aktiv building standard

For Austria, the passive house ÖNORM H 5055 Energy performance of buildings - Energy performance certificate referred to as an energy standard with A - Accompanying document to the Energy Performance Certificate - findings, opinions, advice and recommendations for the - mandatory for all buildings. For an energy efficient house / A are:

In addition, the passive house standard is also in addition to the newer klima: aktiv building standard implemented, where the criteria about 60% seated on the PPHP standard of the Passive House Institute in Darmstadt. There are:

  • Need heating, water heating and auxiliary electricity for heating and ventilation ( heating demand HEB ventilation and air conditioning energy demand RLTEB ) ≤ 65 kWh/m2WNFa
  • Heating demand ( HWB ) ≤ 15 kWh/m2WNFa
  • Airtightness n50 ≤ 0.6 h -1
  • Comfort ventilation optimized ( ÖNORM H 6038 or DIN 1946)

Since 1 January 2007, in Vorarlberg, a law came into force, prescribing the passive construction for all new public buildings mandatory.

Switzerland: Minergie P

In Switzerland the term is not passive house as such. Buildings of this type are classified with a building label Minergie standard, the standard Minergie -P. CA is the Lucerne University - Engineering and Architecture.

History and outlook

The polar ship Fram was named the first truly functional and appropriate use of the passive house principle. This ship was built in 1883. The walls and ceiling were sealed with multiple layers and materials, reaching a thickness of about 40 cm. The window through which the cold was particularly easy to penetrate, were replaced by triple panes. So it was possible that the furnace had not fired, no matter how low the temperature was below zero. The implementation of this idea on a home made ​​in the 1970s and 80s. In Copenhagen, the first house of this kind was built at the " Danish Technical College " 1973. According to current provisions, it is classified as "low energy house". In this research project has provided important insights were gained and laid the foundations for the development of low-energy and subsequently the passive houses.

In these initial projects, but there were significant problems. Neither there were solutions for energy efficient windows, nor was it aware of the importance of lasting airtightness clear. In many projects, also came a very complicated technique is used that does not work reliably at the end and was much too expensive for mass application.

In a " German - Swedish " project they had learned from the experience and made ​​the important things right. You satisfied with the air tightness, good insulation, good windows and reliable controlled ventilation the course for the modern energy-saving houses. The last step of the production-ready passive house was in 1990. A team of German scientists had developed in international cooperation new components such as a CO2 - controlled ventilation and insulated window frames that were efficient and could be manufactured at low cost at the same time.

For this project in 1991 was the first accredited passive house in Germany, which was built in Darmstadt- Kranichstein and Dr. Wolfgang Feist, his time at the Institute for Housing and Environment, planned. The heating energy consumption of four detached units is on average 10 kWh/m2 and has since remained constant. The passive house was a perfect functioning of all components and had at that time an energy saving of around 90 % compared to a conventional house.

The first free-standing passive house was built by oehler faigle archkom 1998 in Bretten. The first German multi-family passive house is located since 1999 in Freiburg, Vauban district. This was followed by passive house settlements in Wiesbaden (21 houses), Hanover -Kronsberg (32 houses) and Stuttgart (52 houses). In the years 1999-2001 another 221 housing units were built in five EU countries ( Germany, France, Austria, Sweden, Switzerland ) at 14 locations in the context of CEPHEUS - all with intensive measurement programs, which confirm the complete fulfillment of expectations.

Europe's first large office building in passive house standard with solar seasonal storage was built in 1998 as headquarters of a company in Coelbe at Marburg. In the meantime, a number are part of larger office buildings have been built to the Passive House standard, such as the energon 2002 in Ulm with a net floor area of ​​6911 square meters and about 420 jobs, or Lu - teco 2006 in Ludwigshafen with 10,000 sqm of office space and more than 500 jobs.

The first time in public housing, the measure was used in 2000 in Kassel ( 40 units). With the Schiestlhaus at high Schwab in 2004 / 05 to 2154 m above sea level. A. the first high-altitude building built in passive house construction. Currently in Vienna created the largest passive house settlement in Europe, the euro gate in the third district of Vienna with 1700 apartments, 700 of the passive house standard.

The first energetically renovated passive skyscraper in the world is located in Freiburg im Breisgau, the high-rise Bugginger Street 50 In the 45 -meter-high building is a 16-storey high-rise building with a floor space of 7,000 sq. meters, built in 1968 in the vineyard district and was renovated in the years 2009 to 2010. It now belongs to the public housing company Freiburg City (FSB).

There are now many thousands of passive houses, inhabited mainly in Germany, Austria, Switzerland and Italy ( South Tyrol), of which several large settlements where the low consumption and good comfort has been confirmed by scientific studies accompanying CEPHEUS. About half of these houses stands in Austria that is a leader in the field of energy -efficient houses. It promotes energy -efficient houses since 1996, and by 2009 about 8,000 apartments in A standard ( passive house ) were carried out, a further 5,000 were in construction / renovation. Meanwhile, the public administration buildings, homes, schools, gyms and even industrial buildings were built with passive house standard, such as when Bambados in Bamberg applied, which is Europe's first passive house indoor swimming pool with six swimming pools, and 1,700 square meters of water surface.

The first passive house in the U.S. was built in 2003 in Urbana, Illinois as a private residence. 2006, another Passive House in the context of social housing in Urbana and the BioHaus school in Bemidji, Minnesota were completed for German as a foreign language program lake with the help of the German Federal Environmental Foundation. Special media presence reached the Austria House in Whistler (British Columbia) for the 2010 Winter Olympic Games in Vancouver, which is running in passive house standard. In North America, this technique is largely unknown, a few dozen houses were only built.

There are passive houses as a solid, wood, clay, construction formwork technology, as polystyrene stone house and other building techniques. In recent times, there are increasing efforts to retrofit older buildings to passive house standard. Essentially doing the same conditions apply as for new construction, but the planning and technical implementation is much more complicated. The first projects were implemented in Hannover, Nuremberg, Ludwigshafen and Frankfurt a M. With these modifications, the energy consumption for heating were each reduced by more than 85%. Used were doing the same principles and components which have been developed for the construction of passive houses.

In summary, it is to say that the passive house principle not invented, but has been developed step by step. In the development of many institutions and individuals were involved who have made an important contribution to the overall concept.