EWI Grants in Cornwall: What Funding Is Available in 2026?

Why solid wall insulation has grant support

Solid-wall properties — homes built before around 1919 without a cavity to fill — account for some of the worst-performing housing in the country when it comes to heat loss. There's no simple loft insulation or cavity fill fix. The only way to significantly improve the thermal performance of a solid-wall house is to add insulation to the outside (EWI) or inside (IWI). External wall insulation is more effective and doesn't reduce internal floor area, but it's expensive relative to other measures.

The government's interest is in getting poorly-insulated homes up to a decent EPC rating, reducing fuel poverty in households with high heating costs, and hitting net-zero targets that depend on dramatically cutting emissions from domestic buildings. Solid-wall homes are disproportionately represented among the lowest EPC bands — D, E, F, and G rated properties — which is why the grant schemes are targeted there. Cornwall has a significant stock of exactly this type of property: pre-1919 granite and stone cottages, terraced Victorian housing, rural farmhouses. The schemes exist partly because of properties like these.

Great British Insulation Scheme (GBIS)

The Great British Insulation Scheme is targeted at homes with an EPC rating of D or below. It's funded through energy company obligations — the large energy suppliers are required to direct a portion of their income toward improving the energy efficiency of poorer-performing homes, and they contract this work out through approved installers.

Under GBIS, solid wall insulation (either internal or external) can be fully or substantially funded for eligible households. There are two routes: a means-tested group (lower income households) and a general group based primarily on EPC rating. The general group doesn't require low income but does require the property to be EPC D or below and in a lower Council Tax band (typically A–D). In Cornwall, where property values historically outran Council Tax banding, a number of households that would otherwise be higher-income will still qualify on Council Tax band alone.

Important caveat: GBIS is managed through energy suppliers and their approved installer networks. You don't apply to the government directly — you check eligibility through an approved installer or the energy supplier you use. The Ofgem website maintains a list of approved contractors.

ECO4 scheme

ECO4 is the current iteration of the Energy Company Obligation scheme, running until 2026. It's targeted more specifically at low-income and fuel-poor households — households receiving certain benefits (Universal Credit, Pension Credit, Housing Benefit, among others) or with a low household income relative to energy costs.

Under ECO4, EWI on a solid-wall low-income home can be fully funded, including all labour and materials. The qualifying criteria are stricter than GBIS on income, but where they are met the scheme is generous. Whole-house measures — not just insulation but windows, heating system upgrades, and other improvements — can sometimes be bundled together under a single referral.

The scheme is administered through energy companies and local authorities. Your local council can sometimes act as a gateway to ECO4 referrals, particularly if you're an older homeowner or in a property with a very poor EPC. It's worth contacting Cornwall Council's housing team directly to ask about referral routes.

Warm Homes Plan

The Warm Homes Plan is the Labour government's flagship domestic energy efficiency programme, announced as part of the 2024 election manifesto and allocated significant capital funding from 2025 onwards. It works alongside rather than replacing ECO4 and GBIS, and adds additional grant funding for homeowners who don't meet the income thresholds for ECO4 but still have poorly-performing properties.

As of mid-2026, the Warm Homes Plan is still being rolled out through local delivery bodies and combined authorities. In Cornwall, delivery is being managed in part through the Combined Authority and local council retrofit programmes. Funding amounts and specific eligibility criteria are subject to local implementation decisions. The headline commitment is grant support of up to £15,000 per household for high-impact measures including solid wall insulation, but the practical availability of that ceiling varies by local scheme.

Cornwall Council and local schemes

Cornwall Council runs its own housing improvement programmes alongside the national schemes. These tend to be targeted at the most vulnerable households — privately owned homes with serious disrepair or fuel poverty risk, older residents, and households identified through the Discretionary Housing Fund. Council-run programmes can sometimes fund work that sits in the gap between national scheme eligibility — households that are just outside the income limits for ECO4 but still cannot afford the work privately.

The simplest starting point is contacting Cornwall Council's Private Sector Housing team, who can advise on what local funding routes are currently active and whether your property and circumstances would qualify. They can also make referrals to national schemes where appropriate.

Eligibility — what actually matters

The two main variables that determine which scheme you can access are your EPC rating and your household income or benefit status. For the EPC, you need an up-to-date certificate (within 10 years, or a new one commissioned). Most solid-wall Cornish cottages that haven't been upgraded will come in at D, E or lower — which puts them squarely in range for GBIS and potentially ECO4.

For income-based schemes (ECO4, elements of the Warm Homes Plan), the qualifying benefits include: Universal Credit, Child Tax Credit, Working Tax Credit, Housing Benefit, Pension Credit (Savings or Guarantee), Income Support, Income-Based JSA, and Income-Related ESA. If anyone in the household receives any of these, it's worth checking ECO4 eligibility.

Listed buildings and properties in Conservation Areas require Listed Building Consent or planning permission for EWI in some cases — this can affect eligibility for grant-funded work or complicate the installation. Worth checking with the planning authority before proceeding.

How to apply

The starting points for most homeowners are:

• →Check the Ofgem register for GBIS/ECO4 approved installers in your area
• →Contact your energy supplier — most large suppliers have a home improvement team who can advise on what you qualify for
• →Contact Cornwall Council Private Sector Housing for local scheme referrals
• →Check the government's Energy Company Obligation eligibility checker at GOV.UK
• →Ask an approved installer to carry out an assessment — they can advise on which schemes apply and handle the paperwork

The application process itself is handled by the installer and energy company, not directly by you. Your role is providing access for an assessment, confirming eligibility information, and agreeing to the work. The paperwork burden on the homeowner is relatively light — most of the administrative work sits with the installer and the scheme administrator.

What the grant covers (and what it doesn't)

Under full-grant schemes (ECO4 for qualifying households) the grant should cover all materials and labour for the EWI installation, including the insulation boards, adhesive, basecoat, mesh, and topcoat render finish. Under partial-grant schemes (GBIS general group, Warm Homes Plan contribution grants) there is typically a customer contribution required — the size of which depends on the total cost and the grant cap.

What grants do not cover: any prep work to rectify pre-existing defects (failed render, structural cracks, rising damp issues), scaffolding on particularly complex or tall properties where costs exceed standard rates, and any separate decorating or internal work. If the wall has significant defects that need fixing before EWI can be applied, that remediation cost sits outside the grant scope.

It's also worth noting that grant-funded work must be carried out by an approved installer registered on the relevant scheme. You can't receive a grant and then use any contractor you choose — the contractor must be on the Ofgem TrustMark or CIGA registers, depending on the scheme.

What we'd tell a Cornish homeowner

If you have a solid-wall property — which covers most pre-1940 construction in North Cornwall — it is worth spending an hour checking your eligibility before you assume EWI is out of budget. The schemes are specifically designed for the type of property stock that makes up a large proportion of housing around Bude, Boscastle, Camelford, and the surrounding area.

We install EWI and we work to the manufacturer specifications required for grant-funded projects. If you're investigating grant options and want a view on what the job would involve practically, We're happy to come and have a look and give you our honest read of what's achievable. We don't do the grant administration — that runs through the approved scheme network — but we can tell you what the installation itself would look like and whether the property is a straightforward candidate or has complications worth knowing about before you start the application process.