With London's housing stock being some of the oldest in the UK, Best Free Insulation And Energy Efficiency Grants In London is a growing concern for both homeowners and tenants. High energy bills, heat loss, and carbon emissions are common issues in poorly insulated homes. Fortunately, several grant programmes—both national and London-specific—now offer free or subsidised insulation and energy efficiency upgrades. These schemes not only help reduce energy costs but also improve living conditions and support the UK's net-zero goals. This guide explores the top energy efficiency grants available in London as of 2025, who is eligible, and how to apply.

The Warm Homes Programme – London's Local Energy Lifeline

The Warm Homes Programme, supported by the Mayor of London and local borough councils, is one of the most comprehensive retrofit schemes in the capital. Relaunched in 2025, the programme targets households with low incomes and poorly insulated homes. It provides grants of up to £30,000 for improvements like loft insulation, cavity wall insulation, underfloor insulation, solar panels, smart heating controls, and even air-source heat pumps. To be eligible, households must typically have an EPC rating of D to G and a total income below £36,000, or receive means-tested benefits such as Universal Credit or Pension Credit. 

Some residents may also qualify based on specific London postcodes considered to be energy priority areas. Applications are made through the London.gov.uk website, where an initial eligibility check leads to a free home assessment. If approved, the upgrades are carried out by approved contractors. With a wide scope of covered measures and deep grant funding, the Warm Homes Programme is the flagship local solution for energy efficiency in London.

ECO4 Scheme – National Grant for Low-Income Households

The Energy Company Obligation (ECO4) scheme is a nationwide programme funded by energy suppliers and managed by the UK government. It mandates large energy companies to support vulnerable and low-income households in upgrading the energy performance of their homes. Running from April 2022 to March 2026, ECO4 focuses on whole-house retrofitting rather than one-off measures. Through ECO4, eligible households can receive free loft insulation, cavity or solid wall insulation, floor insulation, boiler upgrades, and smart heating controls.

 It also funds first-time central heating systems for homes that never had one. To qualify, households must receive one or more income-based benefits, such as Universal Credit, Child Tax Credit, or Housing Benefit, and live in homes with an EPC rating of D to G. Residents in London can apply through their energy supplier, a certified installer, or via support organisations like the Energy Saving Trust or Repowering London. ECO4 is especially valuable because it typically covers the entire cost of installation for qualifying households, making it one of the most accessible and cost-effective schemes in the UK.

Great British Insulation Scheme (GBIS) – A Boost for Middle-Income Homes

The Great British Insulation Scheme (GBIS), formerly known as ECO+, was launched in 2023 and will continue through 2026. Unlike ECO4, this scheme extends support to a wider demographic, including middle-income households and those living in homes within Council Tax bands A–D.GBIS offers a more limited selection of insulation measures, focusing on loft insulation, cavity wall insulation, underfloor insulation, and heating control upgrades. While not all applicants will receive full funding.

many will only pay a small contribution, especially if they live in homes with poor energy performance.This scheme is ideal for households that don't qualify for ECO4 but still need help improving home energy efficiency. Applications can be made through energy suppliers or trusted third-party providers. It's a great option for working families or pensioners on moderate incomes looking for affordable upgrades.

Local Authority Delivery (LAD) Scheme – Council-Led Support

The Local Authority Delivery (LAD) scheme is a government-funded initiative that channels money through borough councils to retrofit energy-inefficient homes. LAD specifically supports households with EPC ratings of D to G and incomes typically below £30,000, although exact thresholds can vary by borough.

Improvements available through LAD include external wall insulation, window upgrades, loft insulation, smart heating controls, and low-carbon heating systems. London boroughs like Hackney, Islington, and Camden have been proactive in delivering LAD grants through partnerships with contractors and housing organisations.

To apply, residents can contact their local council's energy or housing team. If eligible, they'll receive a home energy assessment and may be offered a tailored retrofit package. LAD is an important resource for council tenants, private renters, and homeowners alike, especially where local needs are being prioritised.

Boiler Upgrade Scheme (BUS) – Heat Pump Incentives

While not directly focused on insulation, the Boiler Upgrade Scheme (BUS) provides grants for households looking to replace old gas boilers with low-carbon heating systems. It supports the installation of air source heat pumps, ground source heat pumps, and biomass boilers with grants of up to £7,500.

Unlike other schemes, BUS is not means-tested and is open to any homeowner or landlord in England and Wales, as long as the home meets basic eligibility criteria. The system must replace a fossil-fuel boiler, and the property should have adequate insulation in place to qualify.

Applications are managed by installers, who will apply on the homeowner's behalf once the system design is confirmed. This grant is an excellent complement to other schemes, especially for households committed to transitioning to renewable heating technologies.

Help to Heat Programme – National Framework for Retrofit

The Help to Heat initiative is the UK government's umbrella strategy that includes schemes like ECO4, GBIS, LAD, and the Home Upgrade Grant (HUG). It aims to decarbonise homes and cut bills for the most vulnerable. For Londoners, this means many borough-level and national programmes are working together to provide streamlined support.

If you're not sure which grant applies to you, local energy hubs and retrofit advice centres—such as the Greater London Authority (GLA) Retrofit Advice Service—can help guide you through the maze of funding options. Help to Heat is not a direct grant but a coordinated network making it easier to access home upgrades.

Tips for Applying and Maximising Grant Benefits

Before applying for any grant, it's wise to check your home's current EPC rating. You can do this through the UK government's EPC Register. Knowing your EPC band will help determine which schemes you qualify for. It's also a good idea to gather evidence of income or benefits ahead of time, as this is a common requirement. When choosing an installer, always ensure they are TrustMark registered or certified under the PAS 2035 retrofit framework, which ensures quality and safety. 

Be cautious of cold callers or unsolicited messages promising “free insulation”—scams are unfortunately common in this sector. Finally, don't delay. Many schemes have limited funding windows, and early application increases your chances of approval. Local authorities often have waiting lists, especially for high-demand grants like Warm Homes and LAD.

Conclusion

Energy efficiency grants represent one of the best ways for Londoners to improve their homes in 2025—without spending thousands upfront. Whether you're on a low income, living in a cold home, or just seeking to futureproof your property, there's likely a scheme that fits your needs.

From deep retrofits through the Warm Homes Programme, to wider eligibility under the Great British Insulation Scheme, Londoners have access to some of the most ambitious retrofit support in the UK. By taking action today, you can enjoy lower energy bills, a more comfortable home, and the satisfaction of contributing to a cleaner, greener city.

FAQs

What are the best free insulation and energy efficiency grants in London?

The best free insulation and energy efficiency grants in London include ECO4, Great British Insulation Scheme, and Warmer Homes. These help low-income households reduce energy bills and improve home energy performance at no cost.

Who qualifies for free insulation grants in London?

To qualify for free insulation and energy efficiency grants in London, households typically need to be low-income, receiving benefits, or living in properties with poor energy efficiency (EPC D or below).

How do I apply for energy efficiency grants in London?

You can apply through local council websites, government energy schemes like ECO4, or trusted retrofit providers. Most require a quick eligibility check and documentation such as proof of income or benefits.

What types of insulation are covered under London grants?

Grants may cover cavity wall insulation, loft insulation, underfloor insulation, and sometimes solid wall insulation. The type depends on your property's structure and energy efficiency rating after a survey.

Are private tenants eligible for free energy efficiency grants in London?

Yes, private tenants may qualify if the landlord agrees to the work and the tenant meets eligibility criteria such as income level or benefit receipt. Landlord permission is essential.

Can homeowners get free insulation in London?

Homeowners in London can access free insulation through government schemes if they meet criteria such as low income, benefits, or poor EPC rating. Grants usually cover both assessment and installation.