Passivhaus Standards
There are now three Passivhaus standards for new buildings and one for retrofit, all based on the same reliable approach:
Passivhaus Classic: the original Passivhaus standard, as described in this website. For new buildings this is the minimum standard to be reached before Passivhaus Plus and Passivhaus Premium standards can be awarded.
A Passivhaus Classic will be certified when it meets the following criteria:
Energy
Heating Demand
Peak Heating Load
Primary Energy Demand
Comfort
Low air leakage
Surface Temperatures
Summer Overheating
Ventilation (fresh air)
15 kWh/sq m /year (for a typical 100 sq m house with electricity at 14p/kWh, the annual heating cost is £210 or £4.04 per week).
10 W/sq m (for a typical 100 sq m house a single 1kW heater, or ten 100W light bulbs heats whole Passivhaus on the coldest day of the year).
135 kWh/sq m/year (this is total energy use, including losses in transmission cables, the power station and extracting fuel).
no draughts (0.6 air changes per hour at 50Pa pressure).
17 degrees C or above, even on the coldest day in winter, including windows
No more than 10% of annual hours greater than 25 degrees C, and usually a lot less than this.
Approx. 30 cu m/hour per person; a scientifically proven level of fresh air optimum for health.
Passivhaus Plus
This building will meet the same criteria as Passivhaus Classic with primary energy use met on site with renewable energy sources.
Passivhaus Premium
This is a Passivhaus Classic building where primary energy use is exceeded on site with renewable energy sources.
EnerPHit – Passivhaus for Retrofit
Different targets can be used which address the challenges posed by existing buildings.
For these the EnerPHit criteria for air tightness and heating demand apply, the other criteria being the same as Passivhaus:
EnerPHit Heating Demand 25 kWh/sq m/year.
EnerPHit Peak Heating Load 10 W/sq m.
EnerPHit Air-tightness 1.0 air change per hour at 50Pa pressure (no draughts).