UK Retrofit Costs Explained 2025
Complete Guide to Home Energy Upgrade Costs
Quick Answer
UK retrofit costs range from £300 for draught-proofing to £22,000+ for external wall insulation. Loft insulation costs £300–£1,500, cavity wall insulation £1,500–£3,500, and heat pumps £8,000–£14,000. Government grants can cover 50–100% of some measures.
Retrofitting your home to improve energy efficiency reduces bills, increases comfort, and prepares you for upcoming regulations. With rising energy costs and the October 2030 EPC requirements for landlords, understanding retrofit costs has never been more important.
This guide covers every major retrofit measure from simple draught proofing to whole house deep retrofit, with realistic costs, potential savings, and payback periods for UK homes in 2025.
The Fabric First Approach
Always insulate before upgrading heating systems. A well insulated home needs less heating, meaning smaller (cheaper) heat pumps and lower running costs. The order should be: loft insulation → wall insulation → draught proofing → windows → heating system → renewables.
Insulation
Heating Systems
Windows and Doors
Renewables
Controls and Quick Wins
Whole House Retrofit Packages
Combining measures often makes sense logistically and can improve overall performance.
| Package | Typical Cost | EPC Improvement | Annual Savings |
|---|---|---|---|
| Basic Package (loft, draught proofing, controls) | £1,000 to £2,000 | +8 to 15 points | £250 to £400 |
| Standard Package (+ cavity walls, boiler) | £5,000 to £10,000 | +15 to 25 points | £400 to £700 |
| Deep Retrofit (+ heat pump, solar) | £25,000 to £45,000 | +30 to 50 points | £800 to £1,500 |
| Full Passivhaus Standard | £50,000 to £100,000+ | A rating achievable | £1,500+ |
Available Funding and Grants
Check what grants you qualify for before paying full price. Significant funding is available for many homeowners.
Boiler Upgrade Scheme (BUS)
Eligibility: Any homeowner, valid EPC, no previous grant
Applied for by installer. Check gov.uk for current availability and funding.
ECO4 Scheme
Eligibility: Low income households, certain benefits
Covers insulation, heating, solar. Apply through energy suppliers.
Great British Insulation Scheme
Eligibility: Council tax bands A to D, EPC D to G
Cavity and loft insulation. Wider eligibility than ECO4.
Home Upgrade Grant (HUG2)
Eligibility: Off gas grid homes, low income areas. Scheme closed March 2025. Check gov.uk for successor programmes.
Administered by local authorities. Check availability.
0% VAT on Energy Saving Materials
Eligibility: All homeowners until 2027
Insulation, heat pumps, solar. Labour charged at standard rate.
Key Takeaways
Calculate Your Retrofit Costs
Get a personalised estimate for upgrading your home's energy efficiency.
Use Retrofit CalculatorRelated Guides
EPC Ratings Explained
Understanding A to G ratings and the October 2030 deadline.
Loft Insulation Costs UK
Detailed guide to loft insulation options.
Do I Need Planning Permission UK?
Some retrofit measures need planning approval. Check before you start
Building Regulations Explained
What approvals retrofit work needs.
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