External wall insulation · Hertfordshire
External wall insulation in Hemel Hempstead
Looking for external wall insulation in Hemel Hempstead? We survey homes across Hemel Hempstead and the HP3 area, then give you a fixed written price before any work starts. For homes in Hemel Hempstead, the survey starts with the wall itself: solid brick, stone or concrete, and whether any old render is sound enough to insulate over.
- Free survey in HP3 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Hemel Hempstead
Postcode, service and a phone number is all we need.
Part of every quote
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic
- Work happens outside, so you can live at home throughout
- Installing wall insulation in homes is currently zero-rated for VAT until 31 March 2027
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board

What we look for in Hemel Hempstead
We also cover Berkhamsted and St Albans, close to Hemel Hempstead. Hemel Hempstead is about 7 miles from Watford. The East of England has a mix of post-war estates, inter-war semis and older solid brick and flint cottages, with some system-built council homes on post-war estates.
Much of Hertfordshire sits in the lower wind-driven rain exposure bands, which keeps the choice of finishes wide — though hilltop, coastal and exposed gable walls can still need a tougher specification, so we check the actual site.
Whole-house jobs and single elevations are both quoted in Hemel Hempstead; a cold gable or rear wall can be done on its own where it suits.
- Postcode district
- HP3
- County or area
- Hertfordshire
- Nation
- England
- Nearby
- Berkhamsted, St Albans, Harpenden, Watford
Permissions in England
Before quoting in Hemel Hempstead, we check whether the property is in a conservation area, under an Article 4 direction or listed, because that decides whether changing the outside needs planning permission.
Insulating or re-rendering more than half of a wall's area brings in Part L of the Building Regulations, so building control is notified and the wall is upgraded to about 0.30 W/m²K where practical.
What does the survey check before EWI is specified?
- Wall construction and condition, including any damp, cracking or loose render
- Ground levels and the damp-proof course, so the system starts above splash height
- Eaves depth, verges and whether the roofline needs extending
- Window positions, cill depths and reveal space
- Services on the wall: gas, electric meters, flues, soil pipes, satellite dishes and lights
- Planning and Building Regulations position for your property and nation
External wall insulation prices in Hemel Hempstead
| Item | Guide price | Notes |
|---|---|---|
| EPS system with silicone render | £105–£145 per m²0% VAT | Most common choice for houses |
| Mineral wool system | £125–£170 per m²0% VAT | Non-combustible, vapour-open |
| Brick-slip finish over insulation | £185–£260 per m²0% VAT | Where a brick look is wanted |
| Three-bed semi, EPS + silicone (incl. scaffold) | £10,200–£17,7000% VAT | 80–100 m² of wall; depends on detailing and access |
Confirmed by a fixed written quote after survey. 0% VAT: installing insulation in a home is zero-rated until 31 March 2027, so these figures are the total; 5% applies from 1 April 2027.
How it works
Tell us about the property
Use the quote tool or form, or call. Photos help.
Free survey
We measure, check the walls and confirm approvals.
Fixed written quote
System, details, access, exclusions and VAT in writing.
Installation
Scheduled for suitable weather, with a clear programme.
External wall insulation in Hemel Hempstead: questions
How long does external wall insulation last?
A well-installed render system is commonly expected to last 25–30 years or more, with occasional cleaning and inspection of sealants. The system manufacturer's documentation states the expected service life for the specific build-up.
Do I need planning permission for external wall insulation?
Often not for a house in England or Wales if the finish looks similar to the existing walls. You will usually need permission in a conservation area, on flats, on commercial buildings or where the appearance changes noticeably. Listed buildings need listed building consent. We check your address before quoting.
Does external wall insulation cause damp?
Not when it is specified and detailed properly. Problems usually come from poor detailing: no starter track above the damp-proof course, gaps at cills and penetrations, or a vapour-closed system on a wall that needs to breathe. The survey checks moisture, ground levels and the wall type before a system is chosen.
Do you cover Hemel Hempstead?
Yes — we survey and quote external wall insulation in Hemel Hempstead (HP3) and nearby Berkhamsted, St Albans and Harpenden, with a fixed written price before any work starts.