Joseph Little Architects

The building must not use more than 15 kWh/m² per year in heating energy.
At 50 Pa (N/m²) the building must not leak more air than 0.6 times the house volume per hour.
Total primary energy consumption (primary energy for heating, hot water and electricity) must not be more than 120 kWh/m² per year.
Further, the specific heat load for the heating source at design temperature is recommended, but not required, to be less than 10 W/m².