1. Types of insulation covered
| Measure | Typical cost | HES support |
|---|---|---|
| Loft insulation | £300–£600 | 75% / up to £7,500 |
| Cavity wall | £2,000–£3,000 | Often free via ECO4 |
| Solid wall — external | £12,000–£18,000 | Up to £7,500 grant + loan |
| Solid wall — internal | £3,000–£8,000 | Up to £7,500 grant + loan |
| Flat roof / floor | Varies | HES loan available |
2. Scheme comparison
| Scheme | Funding | Who qualifies | Measures | Status |
|---|---|---|---|---|
| HES | Grant + loan | Owner-occupiers | All types | Ongoing |
| ECO4 | Usually free | Benefits / low income | Loft, cavity, solid wall | Until late 2026 |
| Warmer Homes | Fully funded | Fuel-poor households | All + heating | Ongoing |
| GBIS | Closed | Was CT bands A–E | Loft & cavity | CLOSED March 2026 |
3. ECO4 rural off-gas uplift
Properties off the gas grid score higher under ECO4, making suppliers more likely to fund larger packages — particularly relevant in rural Scotland.
4. Warmer Homes Scotland — fully funded route
For households in or at risk of fuel poverty, Warmer Homes can deliver insulation, heating and windows as part of a whole-house package at no upfront cost.
5. Older Scottish homes
Stone homes and tenements typically have solid walls. There are exemptions if cost-effective measures still leave the home below band C — meaning you don't have to spend disproportionate amounts.
6. TrustMark and PAS 2030/2035
Quality matters
7. The EPC connection
From 2026, EPCs are valid for 5 years and use updated ratings. From 2033, owner-occupiers will be expected to meet EPC band C — insulation is usually the most cost-effective route there.
8. FAQ
Is cavity wall insulation right for my home?+
Most cavity wall homes built after the 1920s benefit. Exposed coastal or driving-rain locations need careful product choice.
What is solid wall insulation?+
Insulation applied to the outside (EWI) or inside (IWI) of solid walls — common in tenements and stone homes that have no cavity.
How does insulation affect my EPC?+
Loft insulation typically adds 5–15 points; solid wall insulation can add 15–30 points.
Can I get free insulation if I am on benefits?+
Yes — ECO4 and Warmer Homes Scotland both fund free insulation for eligible households.
What is the GBIS and is it still available?+
The Great British Insulation Scheme closed to new applications in March 2026. Use HES or ECO4 instead.