How much do warm homes plan funding cost?

The honest answer to "what does this cost?" is that for a lot of households, it costs nothing. The whole point of the Warm Homes Plan grants is to remove or sharply reduce the cost of insulation, heating upgrades and low-carbon technology for the homes that need them most. What you actually pay depends entirely on which scheme you qualify for, so this page sets out the real numbers behind each route, where a grant covers the lot, where it covers part of it, and where you would top up with low-cost finance.

Fully funded routes: £0 to the household

Two schemes can cover the full cost for eligible homes. Under ECO4, a fuel-poor household in an EPC band D to G home, on a qualifying means-tested benefit, can receive a whole-house package, insulation, a heating upgrade, often an air source heat pump, with nothing to pay. Whole-house ECO4 retrofits frequently exceed £15,000 in installed value, yet the household contribution is zero because the work is funded by obligated energy suppliers under Ofgem rules. The council-delivered Warm Homes: Local Grant works the same way for lower-income owner-occupiers and private renters in England, typically gross household income under £36,000 and savings under £16,000, funding an insulation plus low-carbon heating package at no cost.

The Great British Insulation Scheme sits a step below: it funds a single insulation measure, loft, cavity wall, solid wall, room-in-roof or underfloor, and for many households that is largely or fully covered too. The General Group route is the one most people miss. If your home is in Council Tax bands A to D in England (A to E in Scotland and Wales) with an EPC of D or below, you can qualify on band and EPC alone, no benefit required, and get insulation funded.

The Boiler Upgrade Scheme: a fixed grant, then the balance

The Boiler Upgrade Scheme is different. It is a fixed capital grant, not a means-tested package, and it applies to any homeowner in England or Wales replacing a fossil-fuel heating system regardless of income. The grant pays £7,500 towards an air source heat pump, £7,500 towards a ground source heat pump (including water source and shared ground loops), £5,000 towards a biomass boiler, or £2,500 towards an air-to-air heat pump. The grant is deducted directly from your MCS-certified installer's invoice, so you never handle the money and never wait for a refund.

Here is the part many sites gloss over: a typical air source heat pump install runs around £8,000 to £14,000 before the grant, so the £7,500 covers a large slice but rarely all of it. On a £12,500 install you would pay the £5,000 balance. Two things close that gap. First, where the property also needs insulation, ECO4 or GBIS can fund the fabric work separately so the heat pump runs efficiently and you are not paying for it twice. Second, the Warm Homes Plan introduces a new multi-billion-pound finance route offering low or zero-interest loans for households who do not qualify for grants, which can spread the remaining balance over manageable payments.

Worked examples by household type

A family on Universal Credit in an EPC band E home: ECO4 funds cavity and loft insulation plus a heat pump as a bundled package. Cost to the household, £0. A working couple in a Council Tax band B home with an uninsulated loft, not on benefits: GBIS General Group funds loft insulation. Cost, largely or fully covered. A homeowner with an old oil boiler, comfortable income, off the gas grid: the Boiler Upgrade Scheme deducts £7,500 from a £12,500 air source heat pump install, leaving a £5,000 balance, part of which can be met through low-cost finance. Three very different budgets, and in two of the three the household pays nothing.

What can add cost

Even on grant-funded work, a few situations can add to the bill or change the plan. Solid-wall homes need internal or external wall insulation rather than cheaper cavity fill, which is more involved (external wall insulation can also need planning permission in conservation areas). Heat pumps require the right radiators and a hot water cylinder, and the property usually needs to be insulated first under the fabric-first PAS 2035 approach, which is why the assessment comes before any quote. Off-gas-grid and rural homes can face higher costs and patchier scheme coverage. None of these are hidden surprises: a qualified retrofit assessor surveys the home, models the measures in the right order, and tells you what each scheme is paying for before any work starts.

How the figures change through 2026

Timing affects cost too. ECO4 runs to 31 December 2026 with a final application date of 31 March 2026, and GBIS closes to new measures on 31 March 2026. If you are eligible for one of the closing schemes, applying now locks in funding that may not exist in the same form next year. After that, the Warm Homes Plan continues funding through the Warm Homes: Local Grant, the Boiler Upgrade Scheme and the new finance route. We track the transition so you never apply to a scheme that has already shut.

The bottom line

For a large share of UK homes, the cost of getting warmer and cheaper to run is genuinely zero, or a modest balance on a heat pump after the £7,500 grant. The trick is matching your home to the right scheme. The cost ranges below summarise each route, and our two-minute eligibility check tells you which one fits before you commit to anything. For the full eligibility detail on every scheme, see our grants and funding guide, or request a callback and we will map it for you.