Energy-efficient renovation

Energy-efficient renovation (energetische Sanierung) covers all measures to improve a building's energy efficiency – from insulation to replacing the heating system.

GEG obligations (German Building Energy Act):

• Replace heating after 30 years: constant-temperature boilers have to go (§72 GEG)
• 65% renewables rule: new heating systems must use 65% renewable energy
• Insulation obligation: top floor ceiling (U-value max. 0.24 W/m²K)
• Fines for breaches: €5,000–50,000 (checked by the chimney sweep!)

Subsidies (BEG/KfW):

Heating replacement (grant 458):

• Basic subsidy: 30%
• Income bonus: +30% (household income €40,000)
• Climate speed bonus: +20% (until 2028)
• Maximum: 70% subsidy, max. €30,000 eligible costs

Complete renovation (KfW 261):

• Up to €150,000 per residential unit
• Repayment grant: 5–25% depending on the efficiency house standard

Costs of typical measures:

• Façade insulation: €15,000–30,000 (payback: 10–15 years)
• Window replacement: €500–1,000 per window
• Heat pump: €15,000–30,000 (after subsidies: from €9,000!)
• Roof insulation: €15,000–25,000

Important: you MUST apply for the subsidy before placing the order – retroactive applications are rejected!