External wall insulation · West Sussex
External wall insulation in Horsham
Need external wall insulation in Horsham? Tell us about the property and we'll arrange a free survey and a written quote. We plan EWI in Horsham around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Free survey in RH12 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Horsham
Postcode, service and a phone number is all we need.
What you get
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board
- 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
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic
Before we quote in Horsham
We cover Horsham and nearby Crawley, Horley and Haywards Heath. It's roughly 7 miles from Horsham to Crawley, the largest town in West Sussex. Homes across the South East range from inter-war semis and post-war estates, which are mostly cavity-walled, to older solid-walled cottages and Victorian town terraces.
Exposure to wind-driven rain varies across West Sussex: sheltered town streets fare better than walls on high ground or facing the prevailing weather, and the render, beads and cill details are chosen with that in mind.
Whole-house jobs and single elevations are both quoted in Horsham; a cold gable or rear wall can be done on its own where it suits.
- Postcode district
- RH12
- County or area
- West Sussex
- Nation
- England
- Nearby
- Crawley, Horley, Haywards Heath, Burgess Hill
England: planning and regulations
For a house in Horsham, external insulation or render is often permitted development if it looks similar to the existing walls; conservation areas, flats, commercial buildings and listed buildings need permission or consent, so we check your address first.
Building control applies once more than half of a wall is insulated or re-rendered, or more than a quarter of the whole building envelope, and your written quote says how that's handled.
Which homes is EWI suited to?
EWI is mainly used on solid-walled houses (most homes built before about 1920), on post-war concrete and steel-framed houses, on homes where cavity fill isn't possible, and on bungalows and park homes. It also suits flats and blocks where the whole building is treated at once.
It is less straightforward where the walls face a pavement with no room to project, on listed buildings, or where planning rules want the existing brick or stone left visible. A survey picks these up before you commit.
External wall insulation prices in Horsham
| 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.
From enquiry to finished wall
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 Horsham: questions
Can EWI go over pebble dash?
Usually yes. The dash is tested for adhesion and hollow areas; sound dash can be insulated over with additional mechanical fixings, while loose areas are removed first.
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.
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 you cover Horsham?
Yes — we survey and quote external wall insulation in Horsham (RH12) and nearby Crawley, Horley and Haywards Heath, with a fixed written price before any work starts.