Can I apply for two government energy grants at once UK?

Yes, you can combine some UK government energy grants, but not all, the key rule is that two grants cannot cover the same cost for the same measure. For example, you could pair the Boiler Upgrade Scheme with ECO4 insulation funding, as long as each grant pays for a different installation (GOV.UK, 2026). The most-searched figure here is that combining grants can reduce your total outlay by up to £15,000 in some cases.

The ability to combine grants depends on the specific scheme rules. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. However, you cannot double-claim for the same measure, for example, using both ECO4 and GBIS to pay for the same loft insulation job. Eligibility also varies by income, property type, and existing heating system.

Boiler Upgrade Scheme pairs with insulation grants

The Boiler Upgrade Scheme offers £7,500 off an air source heat pump or £5,000 off a biomass boiler, regardless of your income (GOV.UK, 2026). The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. For example, a household could claim the BUS heat pump grant and separately receive ECO4-funded cavity wall insulation, as long as both are installed by certified contractors. Energy Saving Trust confirms that combining grants is allowed when each covers a distinct measure (Energy Saving Trust, 2026).

ECO4 and Great British Insulation Scheme cannot overlap

ECO4 and the Great British Insulation Scheme are both administered by Ofgem and target low-income or vulnerable households, but they cannot be used for the same improvement (Ofgem, 2026). ECO4 fully funds multiple measures like insulation, first-time central heating, and solar panels. GBIS focuses on single insulation measures for a wider group. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.

Smart meter and heat pump grants combine freely

Smart meter installation is free from your energy supplier and does not conflict with any government energy grant (GOV.UK, 2026). You can have a smart meter fitted alongside a BUS heat pump or ECO4 insulation without affecting either grant. Similarly, the Energy Company Obligation (ECO4) allows you to apply for multiple measures under one application, such as loft insulation and a first-time central heating system, as long as your home qualifies. Always check with your installer or scheme administrator before applying to avoid delays.

A worked example

A typical 1930s semi-detached home in Manchester could combine the Boiler Upgrade Scheme (BUS) with the Great British Insulation Scheme (GBIS) and reduce total upfront costs by roughly £11,000. This household installs an air source heat pump for £12,000, receiving the full £7,500 BUS grant, leaving a heat pump cost of £4,500. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. The combined grant value of £10,000 brings their total outlay to just £4,500 for both the heat pump and insulation. Annual energy savings, based on Energy Saving Trust figures for a gas-heated semi-detached home, are around £570. At that rate, the payback on their £4,500 investment is roughly eight years, with total savings exceeding £14,000 over the heat pump’s 25-year lifespan.

What homeowners often get wrong

The most common mistake is assuming you can use two grants to pay for the same installation, which is prohibited under all UK schemes. Here are three frequent errors that cost homeowners time and money.

1. Applying for BUS and ECO4 for the same heat pump Many people think they can claim £7,500 from BUS and additional ECO4 funding for the same heat pump installation. This is not allowed, ECO4 only covers heating measures if you are not eligible for BUS or if the heat pump is a secondary measure alongside primary insulation work. Trying to double-claim can delay your application by months and may result in a rejected grant.
2. Assuming income-based and universal grants are separate pots Homeowners often believe ECO4 (income-based) and GBIS (universal) are completely separate and can be stacked for the same insulation job. In reality, both schemes are part of the same Energy Company Obligation framework. You cannot use ECO4 and GBIS to pay for the same loft or cavity wall insulation, you must choose one scheme per measure. Choosing the wrong one could leave you with a £2,000 gap in funding.
3. Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6). Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6). If you fail to separate the grant-funded portion from your own payment, you could be charged the full 20% VAT on the entire invoice, adding hundreds of pounds to your final bill.

Quick reference

• The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
• ECO4 and GBIS cannot be combined for the same insulation job as both are part of the same Energy Company Obligation programme.
• To combine grants, each installation must be a separate, identifiable measure with its own invoice and MCS certificate.
• Combining BUS with ECO4 insulation can reduce your total outlay by up to £10,000 on a typical semi-detached home.
• Always check with your installer that both schemes accept the same property before you sign any contracts, otherwise you risk losing one grant entirely.