The Passive house design standard is the only system in the world for which the ‘design’ energy use can be proven to match the end product. It is theorectically quite simple in its approach, but not so easy to achieve in reality. It’s baseline requirement is a maximum energy consumption per square metre, but to achieve this minimum comfort and construction standards must be met. These standards are well documented elsewhere the following links provide a good reference
Basically buildings designed to passive house principles (and this can be any habitable building type, i.e homes, offices, hosiptals, schools etc) will have an interior enviroment free of draughts and free from cold spots, have continous fresh air input all year round creating a healthy comfortable internal enviroment. They can have openable windows for summer cooling and may require minmal heating in the coldest periods.
Advantages of a Passive house
- The minimal heating required can be supplied via the ventilation system, removing the need for radiators and underfloor heating. Towel radiators are commonly provided in bathrooms.
- The temperature is stable so no need to put the heating on after being away for a couple of days, no fiddling with thermostats or timers.
- The triple glazing provides good acoustic seperation providing a calm interior
- Pollen filtration to vent system provides an advantage to pollen allergy sufferers, and generally provides excellent indoor air quality.
- Thermal envelope consistancy and quality ensure longevity of construction by elimination of condensation internally or within construction.
- Summer time overheating is accounted for in the design, so weather extremes are considered.
- Upfront cost – the extra over to build a passve house is shrinking for new build as current building regulation requirements close the gap between conventional and Passive House buildings. The extra over for refurbishment projects is more variable and depends on the building type/construction and the required depth of refurbishment.
- Dependancy on ventilation system – occupants must learn to clean replace filters as required, and and faults rectified quickly. Spares must be readily available and tecnicians to undertake repairs.