Why almost nobody reaches 70%
Adding every component gives 85%. Payments stop at 70%, and most households fall short of that long before the cap matters.
Where the percentage points get lost
The income bonus needs taxable household income up to €40,000 and owner occupation. The speed bonus needs a qualifying old or fossil system replaced by the end of 2028, also with owner occupation. The efficiency bonus hangs on the technology: a natural refrigerant, or ground, water or wastewater heat.
A household on €55,000 with a newer gas boiler and a standard air source unit lands at 30%. That is the rate to plan with.
What installer adverts say
“Up to 70% funded” is accurate and still misleading when nobody has checked your case. Ask for the rate for your household, in writing, inside the quote.
Source: KfW programme 458, rates and conditions. Checked on 26 October 2026.