Sustainable Homes Scotland
What is a Passive House
What is a Passive House?
The Passive House (German: Passivhaus) is a voluntary building standard, that exceeds the present regulations by far. Built according to this standard the need for heating will be reduced by 90%. Compared to conventional build, which has an average heating demand of 150kWh/m2a, these homes need only 15kWh/m2a.
- The remaining heating and hot water demand can be covered almost completely by renewable energies.
- Zero Carbon Housing will be archieved by additionally reducing the electricity demand and alternative means of supply.
What is the technology behind a passive house?
The so called thermal envelope of a building has to be established and optimised concerning heat conservation and gain, only by means of construction = passive, in contrast to active heating via a oil or gas burner or electric heater. This can be achieved by the following twofold ways:
A) Minimising the heat losses:
- All round super insulation of floor, walls and roof.
- Avoiding of all cold bridging.
- Strict draft proofing throughout the thermal envelope.
- Special triple glazing and super window frames.
- Minimal window sizes facing the North.
- Controlled / mechanical ventilation with heat exchanger.
B) Maximising the heat gains:
- Natural air conditioning through the ventilation ground pipe. The fresh air is pre-heated in winter and cooled in summer.
- Optimal orientation of the home for maximised solar gains.
- Maximising the South facing window sizes.
- Special coating on the windows.
This is the rule of thumb:
Get your thermal envelope right first and then calculate how much the remaining heating demand is, in order to correctly choose and dimension the renewable energy sources and back up heating.