Efficiency is mandatory in 2026
The GEG and restructured KfW programmes make efficient construction a legal baseline. New heating must obtain at least 65% of its energy from renewable sources; in practice this means a heat pump, biomass, a qualifying hybrid or a heat network.
Efficiency House 55 is common for new homes and Efficiency House 40 is the threshold for major KfW funding. The additional €8,000–€25,000 often pays back in 12–18 years with support.
Three elements of modern home energy
Air-to-water heat pumps cost €18,000–€32,000 including buffer storage. An 8–14 kWp PV system with 8–14 kWh storage raises self-consumption to 65–80%; total investment is €18,000–€35,000.
The building envelope—insulation, Uw below 0.9, airtightness and heat-recovery ventilation—is the largest lever. Factory production gives prefabricated construction a precision advantage.
What pays in 2026
For many households the strongest package is Efficiency House 40, heat pump, 10–12 kWp PV, 10 kWh storage and controlled ventilation. Added cost is €28,000–€45,000, with funding covering 30–40%.
Direct electric heating, ventilation without heat recovery and oversized storage are less attractive. Prepare the electrical board for a wallbox, but do not oversize a battery for a future car.
