What is Passivhaus?
Passivhaus refers to voluntary, ultra-low energy construction standard first developed over a decade ago by Dr Wolfgang Feist of the Passivhaus Institute in Germany.
Passivhaus or ‘Passive House’ is the fastest growing energy performance standard in the world with 30,000 buildings realised to date with the majority of those since the turn of the century.
This robust approach to building design allows the designer to minimise the ‘Heating Demand’ of the building and in some residential buildings only specify a heated towel rail as means of conventional heating, this heat can then be recovered and circulated by a Mechanical Ventilation and Heat Recovery (MVHR) unit.
What does The Passivhaus Standard require?
- A maximum space heating and cooling demand of less than 15 kWh/m²/year or a maximum heating and cooling load of 10W/m².
- A maximum total primary energy demand of 120 kWh/m²/year.
- An air change rate of no more than 0.6 air changes per hour at 50 Pa.
How to typically achieve the Passivhaus Standard in the UK
- Very high levels of insulation with minimal thermal bridges
- Extremely high performance windows with insulated frames
- Airtight building fabric
- ‘Thermal bridge free’ construction
- A mechanical ventilation system with highly efficient heat recovery
- Passive solar gains and internal sources