External wall insulation in Harpenden
If you live in Harpenden (AL5) and your walls are solid, system-built or simply cold, external wall insulation may be the most effective upgrade you can make without losing any room inside.
Homes in and around Harpenden
Harpenden is in the AL5 postcode district, about 11 miles from Watford. 6 other towns we cover are within 25 miles.
We arrange surveys in Harpenden (AL5) at a time that suits you, and cover neighbouring St Albans, Luton and Hemel Hempstead too.
We photograph every hidden layer as it goes on, so you have a record of what's behind the finish on your Harpenden home.
Nearby towns we cover: St Albans (5 miles), Luton (5 miles), Hemel Hempstead (6 miles), Welwyn Garden City (7 miles), Hatfield (7 miles), Dunstable (9 miles).
External wall insulation prices in Harpenden
Guide prices for external wall insulation in Harpenden run from about £109 to £175 per square metre installed, depending on system and finish; scaffolding priced per house, with VAT at 0% on homes until 31 March 2027.
Bays, gables, conservatory junctions and narrow side passages take longer than plain walls, so the survey prices your actual house rather than an average.
Popular services in Harpenden
- EWI installation
- Mineral wool EWI
- Insulating lime render
- Silicone render finish
- Non-traditional houses
- Detached house EWI
- Flats & low-rise blocks
- Social housing EWI
- Failed EWI remediation
- EWI surveys
- All 24 services
Rules that apply in Harpenden
- Funding
- Low-income households in homes rated below EPC C can apply for Warm Homes: Local Grant where their council is taking part. The Great British Insulation Scheme closed on 31 March 2026, and ECO4 closes on 31 December 2026; its final months are for finishing and putting right existing work. Grant schemes use their own approved installers, so check a scheme's installer rules before booking; our quotes are for privately funded work unless we confirm otherwise in writing. Grants guide
- VAT
- Installing insulation in a home is zero-rated for VAT until 31 March 2027, then 5%.
Checked October 2026. Rules change, so we confirm them for your address at survey.
External wall insulation in Harpenden: questions
How much should I budget for external wall insulation in Harpenden?
Budget around £109–£175 per square metre of wall for the system and finish, plus scaffolding priced per house. The survey measures your walls in Harpenden and fixes the total in writing.
Do you cover St Albans as well as Harpenden?
Yes. From Harpenden we also cover St Albans, Luton and Hemel Hempstead, and the rest of Hertfordshire.
Which EWI system suits homes in Harpenden?
It depends on the walls. Most brick houses in Harpenden suit EPS with silicone render; older stone or lime-built walls suit wood fibre or insulating lime render; and blocks need mineral wool. The free survey recommends one and explains why.