A passive house is one where heat-losses are reduced to such a degree that no separate heating is necessary, due to a combination of passive solar gain through windows on the south side, body heat, light bulbs, and other heat from cookers, fridges, washing machines, dishwashers, etc. Super insulation, absolute air-tightness, elimination of all cold bridging combined with a heat-recovery ventilation system are the key elements of a Passive house. These elements can be easily achieved using Sipframe SIPs combined with high performance windows & doors.
the Zero-Energy Home
The U-values of the exterior building components generally range between 0.1 and 0.15 W/m2 C. It is a part of the Passive House philosophy that renewable energy technologies are also used to minimize the other sources of energy consumption in the building, notably electricity for household appliances, provided by PV, Wind or Hydro power, and hot water for space heating and domestic hot water, provided by heat pumps, biomass boilers and solar thermal panels. Passive house is the term mostly used, but this type of house can also be called: Zero-Energy House, a house where all the heating and power can be provided on site.
Passive houses should be built at costs no higher than 6% to 8% of traditionally constructed buildings. Sipframe has estimated that energy savings will compensate any eventual higher building costs within in the first 5 years.
The super insulated building layer of a Sipframe SIP leads to a very balanced temperature increasing the thermal comfort. Normal air drafts - often arising at large double-glazed windows with corresponding reactions at the cooler inner windowpanes - are not known. The filtered fresh air shows a lower amount of dust and pollen leading to specific advantages for persons suffering from an allergy. The comfort in summer depends on the quantity of glass surfaces and on the efficiency of shading systems. Regarding their living comfort passive houses normally exceeds conventional buildings.
a breath of fresh air
Passive Houses have a continuous supply of fresh air, optimised to ensure occupant comfort. The flow is regulated to deliver precisely the quantity required for excellent indoor air quality. A high performance heat exchanger is used to transfer the heat contained in the vented indoor air to the incoming fresh air. The two airflows are not mixed. On particularly cold days, the supply air can receive supplementary heating when required. Additional fresh air preheating in a subsoil heat exchanger is possible, which further reduces the need for supplementary air heating.
A heat pump system can also be fitted on the heat recovery system to extract heat from the exhaust air, which can then be used to produce hot water and/or pre-heat the fresh air supplied.
In Germany, experts predict a substantial development in the passive and low-energy house market. In a survey done in 2004 among 180 architects, engineers and house-manufacturers it was estimated that on average, nearly every fifth new building will be a Passive house, and every third, a Low-energy house by the year 2010.
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In UK the Chancellor has announced that newly built ‘carbon neutral’ homes will be exempt from Stamp Duty from April 2007 for at least 3 years. This will apply to all homes sold at over £125,000 in UK.
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