What is Passive House?
Passive House is a building standard that is truly energy efficient, comfortable, affordable and ecological at the same time.
Passive House is not a brand name, but a construction concept that can be applied by anyone and that has withstood testing of performance. But a Passive House is more than just a low-energy building.
What are the Passive House benefits?
Special windows and a building shell consisting of highly insulated exterior walls, roof and floor slab keep the desired warmth in the house – or undesirable heat out.
Passive House buildings allow for energy savings of up to 90% compared with typical existing buildings and over 75% compared with average new best-practice constructions. Similar energy savings have been demonstrated in warm climates where buildings require more energy for cooling than for heating.
Passive House buildings are also praised for their high level of comfort. They use energy sources inside the building such as the body heat from the residents or solar heat entering the building – making heating a lot easier.
A ventilation system consistently supplies fresh air making for superior air quality without causing any unpleasant draughts. A highly efficient heat recovery unit allows for the heat contained in the exhaust air to be re-used.
How Passive House works?
Passive House is fundamentally about design. It is best approached as an integrated design process with the whole design team involved. As a fabric-first standard, it ensured a design delivers very high performance for the lifetime of the building. It relies on building physics and carefully integrated, minimal building services and technology. By eliminating the need to bolt expensive additional technology onto a poorly performing building, it eliminates the risk of bolt-on green-bling compromising the architecture.
Passive House is possible and suitable anywhere in the world. Rural, suburban and urban locations are all possible. Verified location-specific climate data must be used in the design process. Initially started in Germany and then spread in northern Europe. Now there are certified Passive House buildings all over Europe and Scandinavia as well as in the US, Canada, Mexico, Indonesia, New Zealand, Australia, Japan, China, South Korea and other places.
The international Passive House Standard is not the same as “Passive Solar Design.” It does not require buildings to strictly face north or to include significant thermal mass. While solar heat gain is still an important factor in reducing energy consumption and orientation remains important, it is calculated accurately within the Passive House Planning Package as part of the design process so it is always optimised not maximised.
Passive House does not dictate a particular building shape or form. However, the laws of physics are clear: a more complex form with increased surface area will lose more heat than a simple form with less surface area. The more external surface area a building has relative to the usable floor area, the more energy will be needed to heat, cool and ventilate the internal space. Buildings with complex forms can achieve the international Passive House Standard, however, more insulation and costly details will be needed.
Passive House does not require a specific construction system or material. It works with almost all construction systems – timber, steel, concrete, straw, hybrids, you name it. It focusses specifically on ensuring that the building fabric performs to the highest standard of airtightness and thermal insulation. This allows building services to be simplified and minimised – the fabric does all the heavy lifting of keeping the building warm and cool.
The Passive House Certification process
Buildings meeting the strict Passive House certification criteria can be certified as Passive House buildings by any of the Passive House Institute accredited Building Certifiers operative worldwide. Locate your local Passive House Certifiers and other professionals here.
APHA recommend contacting a Passive House Certifier early on in the planning process, where any problems identified can be easily corrected at this point in time. In principle, certification can also be applied for after completion of the building.
As a rule, all energy-relevant planning documents and technical data of the construction products are submitted before the start of construction work. After careful checking and comparison with the energy balance calculation, the certifier will provide information about any necessary corrections.
After completion of the construction, any changes in the planning will be updated and documents relating to construction will be checked during the final inspection