Internal wall insulation · Wales
Internal wall insulation in West Glamorgan
We provide internal wall insulation across West Glamorgan, including Swansea, Neath and Briton Ferry, with a free survey and fixed written price. We plan internal insulation in West Glamorgan homes room by room so you keep the rest of the house usable.
- Free survey and fixed written price
- Guide price from £75 per m² 0% VAT
- Planning and building control checked for Wales
Free survey in West Glamorgan
Tell us the postcode and what you need.
What you get
- Needs careful detailing at floor joists, reveals and corners
- Insulated plasterboard, stud wall or breathable systems
- Can be done one room at a time during a renovation
- Loses roughly 50–100mm per insulated wall
- Keeps the outside of the house exactly as it is

Local considerations in West Glamorgan
South Wales has long runs of solid-wall valley terraces, Victorian and Edwardian town housing and post-war council estates.
Parts of West Glamorgan fall in the higher wind-driven rain exposure bands, especially coastal and upland sites, so render specification, movement joints and detailing at cills, verges and the base of the wall matter more than usual.
We plan internal insulation in West Glamorgan homes room by room so you keep the rest of the house usable.
- Nation
- Wales
- Region
- South Wales
- Towns covered
- Swansea, Neath, Briton Ferry, Port Talbot, Gorseinon
- Guide price
- From £75 per m² 0% VAT
Approvals in Wales
Internal insulation rarely needs planning permission, but in England and Wales insulating or replastering more than half of a wall's area involves building control, and listed buildings need consent for internal changes that affect their character.
The Building Regulations as they apply in Wales treat insulating or re-rendering more than half of a wall's area, or more than a quarter of the building's whole envelope, as renovating a thermal element, with Approved Document L (Wales) setting the target. Building control is involved before work starts.
What are the options for internal insulation?
- Insulated plasterboard — PIR or phenolic foam bonded to plasterboard, fixed to the wall and skimmed. Thinnest option.
- Insulated stud wall — a timber or metal frame filled with insulation, with a vapour control layer and plasterboard. Takes more space but runs services easily.
- Wood fibre and lime — breathable boards finished in lime plaster, for older walls that need to manage moisture.
Internal wall insulation prices in West Glamorgan
| Item | Guide price | Notes |
|---|---|---|
| Insulated plasterboard, supplied and skimmed | £75–£110 per m²0% VAT | |
| Insulated stud wall | £90–£130 per m²0% VAT | |
| Typical bedroom, one external wall | £1,795–£2,9950% VAT | Including making good |
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.
Internal wall insulation in West Glamorgan: questions
Can I stay in the house?
Yes, but each room is out of use while it's worked on, typically 3–5 days.
What happens to my radiators and sockets?
They're taken off and refitted on the new wall face. Electrical work is done by a qualified electrician.
How much room space will I lose?
Usually 50–100mm on each insulated wall, depending on the system.
Do you cover all of West Glamorgan?
Yes. We survey and quote internal wall insulation across West Glamorgan, including Swansea, Neath, Briton Ferry, Port Talbot, Gorseinon.
Do I need planning permission in Wales?
Permitted development rules for houses in Wales are similar to England's: a similar-appearance finish on a house is often permitted, while conservation areas, National Parks, Areas of Outstanding Natural Beauty, flats, commercial buildings and listed buildings need permission or consent. We check your address before quoting.