Get Free Cavity Wall Insulation
Cavity wall insulation is one of the most effective ways to reduce heat loss in your home. Through government-funded schemes, you can get it completely free.
Two Routes to Free Cavity Wall Insulation
ECO4 — With Qualifying Benefits
If you receive Universal Credit energy grants, Pension Credit, JSA, ESA, or other qualifying benefits, and your home has an EPC of D or below, cavity wall insulation is fully funded through ECO4.
Non-benefit routes
The GOV.UK GBIS referral service closed on 31 March 2026. If you are not on benefits, check LA Flex, Warm Homes, local authority and supplier-led routes; eligibility varies by area and property need.
How Much Does It Save?
- Detached house: up to £595/year
- Semi-detached: up to £395/year
- Mid-terrace: up to £195/year
- Bungalow: up to £295/year
These savings add up to thousands over the life of the insulation, which lasts 25+ years with no maintenance.
The Installation Process
- Small 22mm holes drilled in external mortar joints
- Insulation material (mineral wool, polystyrene beads, or foam) injected into the cavity
- Holes sealed and colour-matched to your mortar
- Takes 2-3 hours — no internal disruption
Does My Home Have Cavity Walls?
Most homes built between 1920 and 1990 have cavity walls. If all your external bricks are the same length (stretcher bond pattern), you likely have cavity walls. Your EPC certificate also states your wall type.
Check Current Routes
Check your eligibility in 60 seconds for ECO4, LA Flex, Warm Homes and current supplier-led insulation routes.