The Passive House – sustainable, affordable, comfortable, versatile
No matter the climate or geographical region, Passive Houses stay at a comfortable temperature year round with minimal energy inputs. Such buildings are heated “passively”, making efficient use of the sun, internal heat sources and heat recovery so that conventional heating systems are rendered unnecessary throughout even the coldest of winters. During warmer months, Passive Houses make use of passive cooling techniques such as strategic shading to keep comfortably cool. Either way, a Passive House’s high quality insulation keeps the temperature comfortable, just where it is needed.
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! In terms of heating oil, Passive Houses use less than 1.5 litres per square meter. Vast savings have also been demonstrated in warm climates where buildings typically require active cooling throughout the summer. As energy savings equals emissions reductions, the Passive House is a sustainable alternative to conventional construction.
Passive Houses do not require heating and cooling systems on conventional scales, meaning that the money that would have gone towards larger heating and cooling systems can be spent instead on better windows, thicker insulation and a ventilation system – hallmarks of Passive House design.
Measurements taken from Germany’s first Passive House built in Darmstadt in 1991, show that even when daily highs have fallen to -14°C, the indoor temperatures consistently remained above 20°C without the use of a conventional heating system. The heating demand was shown to be so low, that two 75W light bulbs would have been enough to heat a 20m² room.
Add to this the long-term energy savings Passive Houses bring, particularly in light of the planet’s dwindling non-renewable energy resources, and it becomes clear that Passive Houses are a good investment: both for your wallet and our climate.
Passive Houses not only save money over the long term, especially in light of rising energy costs, but are surprisingly affordable to begin with. The investment in higher quality building components required by the Passive House standard is mitigated by the elimination of expensive heating and cooling systems. The financial support increasingly available in many countries makes building a Passive House all the more feasible.
Even so, Passive Houses do cost more upfront than their conventional counterparts. On average, someone building a Passive House in Germany might expect to spend about 8% more, and this cost differential is likely more in countries where Passive House components are not yet readily available. As the number of Passive House suitable components on the market increases, however, prices in these other countries will drop. Financial support for Passive Houses, as currently available in a number of countries, further reduces their cost. In this light then, building a Passive House may even be more affordable over the long term than building a conventional home.
Ask your regional or national authority for details on support for Passive Houses in your area. More information on aid programmes can be found under the Funding section of this website, coming soon.
Passive Houses may be known for their drastically lower energy use and associated energy costs, but it is the level of comfort they offer that their residents appreciate most. An extremely well insulated building envelope as well as triple glazed windows* and insulated frames keep the desired warmth or lack thereof inside. This means that the floor and all interior walls stay at the same pleasant temperature.
Even the fresh air supplied to Passive Houses is brought to a pleasant temperature before it enters the house. A highly efficient heat recovery system is capable of transferring more than 75% of the perceivable warmth from the used, exhaust air to the fresh, incoming supply air. In this way, for example, 20°C exhaust air can bring the cold supply air on a 0°C day to at least 16°C, without the use of active heating. When it is too hot outside, warm ambient air can be cooled before it enters the home in much the same way.
The ventilation systems in Passive Houses consistently supply fresh air, making for superior indoor air quality. The air in a Passive House never gets stale or stuffy as it does in typical homes when the windows are left unopened. The ventilation systems found in Passive Houses provide plentiful fresh, pollen-free and dust-free air. This maximises comfort for all, especially for those with allergies or respiratory problems.
The pleasant temperatures within Passive Houses and the quality ventilation they offer prevent moisture build up, putting a stop to both the condensation that commonly forms along window frames and mould growth.**
** warm, humid climates may benefit from an extra dehumidification system for this purpose
With over 40,000 Passive Houses in use worldwide and 20,000 in Germany alone, the Passive House Standard is gaining popularity. This is not only due to the outstanding advantages it offers, but also due to its flexibility.
The Passive House Standard, being a quality standard, dictates no particular methods of construction. Whether solid construction, wood or composite- architects can design Passive Houses according to their own preferences. Even manufacturers of prefabricated houses are offering Passive House designs. The versatile Passive House Standard is also increasingly being used in retrofits as well as for non-residential buildings such as schools, administrative buildings, manufacturing plants and hotels. As the Passive House concept is based on physical principles, each building can and should be adapted to its particular climate.