Standard: Gebäudeenergiegesetz (GEG), binding in Germany since November 1, 2020; comparable requirements apply in Austria and Switzerland.
Required U-values
- External wall: ≤ 0.24 W/m²K
- Roof: ≤ 0.20 W/m²K
- Ground floor: ≤ 0.30 W/m²K
Climate
Heating Degree Days (HDD): 3,200 (Germany average).
Typical energy price (for savings estimation)
Natural gas: ~0.12 EUR/kWh (BDEW reference, 2025–2026).
Electric heating: ~0.40 EUR/kWh.
These values are used as defaults in the insulation calculator — you can override the energy price field.