PassivHaus standard - Level 4

[sony]

The basic idea of a Passive House is to reduce the energy usage of a home by 90% compared to existing building stock and has been suggested as a better way to acheive the government's zero carbon aspirations. The principle of the PASSIV HAUS is a building with no heating system except for the heat recovery through the ventilation unit. If built correctly the buildings are robust, healthy and cost effective.
The government considers Passivhaus to be broadly equivalent to Code Level 4 (using SAP) or a 44% reduction in CO² against the requirements of the Building Regulations Part L 2006

The PassivHaus Institut lays down the standard for PassivHaus construction and, on completion, provides certification for buildings which meet its standard.

For a dwelling to qualify as a 'PassivHaus' the following criteria must be achieved:

Space heating: less than 15 kWh/m2/yr

Total primary energy use (heating, hot water and electricity): no more than 120 kWh/m2/yr

Air leakage: no more than 0.75 m3/m2hr @ 50 Pa (0.6 air changes per hour)

The specific heat load for the heating source at the desired temperature is recommended, but not required, to be less than 10 W/m2

Passivhaus its heat loss is so low, and associated carbon emissions so few, that compliance with Code level 4 becomes significantly easier to achieve, and in many cases it can even be achieved automatically."