Grants & funding Cost Calculator

How this calculator works

Every figure in this calculator is the one published in the cost table on our grants & funding guide. Pick the option that matches your job and the calculator returns that published range, adjusted for your region - it does not model anything the guide does not already say.

That is deliberate. A calculator whose rates drift from the page it sits under is worse than no calculator, because two numbers on the same site disagree.

What it cannot know: access, the condition of what is already there, and anything structural. Those are what separate three real quotes from each other.

How the £7,500 Boiler Upgrade Scheme grant works

If you’re in England or Wales, the Boiler Upgrade Scheme takes £7,500 straight off an air-source or ground-source heat pump. A biomass boiler gets £5,000 instead. The figures in the calculator above are the full install price – the grant comes off the top, so what you actually pay is lower. You can check the current terms on the gov.uk Boiler Upgrade Scheme page.

You don’t apply for it yourself. Your installer does, and they have to be MCS-certified for the grant to be paid – that’s a condition of the scheme, not a sales pitch. They put in the application, the £7,500 is deducted from your quote, and you settle the balance. If a quote doesn’t mention the grant at all, ask why before you sign.

The property has to meet a few conditions too. You need to own the home, and the heat pump usually has to replace a fossil-fuel system like gas, oil or LPG rather than an existing electric setup. Your installer will confirm whether yours qualifies before the work is booked, because they carry the risk if the application is refused.

What the grant won’t pay for: bigger radiators, a new hot water cylinder, or the controls and pipework a heat pump often needs to run well. Those sit inside the install cost, not on top of the grant. Price them in early, because an undersized radiator is the usual reason a heat pump underperforms.

Off the gas grid, the deal is better. From 21 July 2026 homes heated by oil or LPG can get £9,000 towards a heat pump rather than £7,500. Rural properties are exactly where a heat pump tends to pay back fastest, since the alternative is expensive bottled or delivered fuel. Again, the gov.uk page above has the live figures – check them before you budget, as scheme rates do change.