Quality blocks — KfW55
Target standard
Facade insulation
High
Current: Poor
Required: High-efficiency external insulation (WLG 032, ≥16 cm)
Roof insulation
Medium
Current: Medium, 12 cm
Required: Top-up to ≥22 cm mineral wool
Windows & doors
High
Current: Old double-glazing, Uw ≈ 2.8
Required: Triple-glazing, Uw ≤ 0.9
Heating system
High
Current: Gas heating
Required: Heat pump or equivalent efficient heating system
Ventilation
Medium
Current: Passive ventilation
Required: Controlled ventilation with heat recovery
Renewable energy
Medium
Current: None
Required: PV system ≥ 5 kWp (optional but recommended)
Energy consumption level
High
Current: ≈ 215 kWh/m²·a
Required: ≤ 55 kWh/m²·a (KfW55)
CO₂ performance
High
Current: High
Required: Reduced ≥ 60% vs. baseline