DE EN
Boiler Upgrade Scheme · KfW 458

Check the grant first. Compare quotes second.

In England and Wales the Boiler Upgrade Scheme pays a flat £7,500 towards an air source or ground source heat pump. In Germany, KfW programme 458 pays 30% up to a cap of 70% of at most €30,000 in eligible costs. The calculator shows your net cost as a range, split by component. Checked on 26 October 2026.

Estimate my net costSee the UK rules

£7,500flat grant, England / Wales
70%German cap
€30,000eligible cost cap, Germany

How the German rate is built

Every eligible system gets the base grant. Bonuses attach to conditions that are often decided inside the installer quote, such as the refrigerant.

Base grant
30%
Efficiency bonus
+ 5%
Speed bonus
+ 20%
Income bonus
+ 30%
Total, capped
max 70%

UK: £7,500, one fixed amount

No percentage, no income test. Your MCS certified installer claims it from Ofgem and takes it off the quote. Biomass gets £5,000 and only fits rural homes off the gas grid.

BUS in detail

Germany: 30% is the floor

Extra bonuses add 5, 20 or 30 points for specific cases. Most households land between 30% and 55%, below the 70% cap.

Why 70% rarely happens

Costs: £9,000 to £15,000

The typical UK range for an air source heat pump supplied and fitted. A market range from published installer quotes, not an official price.

Four steps to your net cost

  1. 1

    Describe the home

    Type and floor area. 120 m² is prefilled; your EPC shows the real figure.

  2. 2

    Name the old system

    Gas, oil, direct electric or night storage. The German speed bonus hangs on this answer.

  3. 3

    Pick the new system

    Air, ground or water source. Costs, grant and net update at once.

  4. 4

    Take the result with you

    Three charts show the cost split, the grant build-up and 20 years of savings.

Order decides the money: in Germany, file the KfW application and wait for approval before you sign with an installer. Signing first voids the claim. At €30,000 of costs and the full rate, that is €21,000.

Questions people ask

Do I need an EPC?

Your installer will look at the property and its EPC where one exists. What an EPC is and how to find yours is in the EPC guide.

Does the calculator store my answers?

No. It runs in your browser and sends nothing anywhere.

Is 70% normal in Germany?

No. 70% is the ceiling. It takes the base grant plus the speed and income bonuses together, and the sum is then capped.

Sources: GOV.UK and Ofgem on the Boiler Upgrade Scheme; KfW programme 458 and BAFA (Germany). Checked on 26 October 2026. Cost ranges are estimates from published installer quotes, not official prices.