Solid wall insulation · Wales
Solid wall insulation in South Glamorgan
Solid wall insulation across South Glamorgan: measured survey, clear specification and a fixed written price before any work starts. On solid-walled houses in South Glamorgan, the gable or the most weather-exposed wall is often the place to start.
- Free survey and fixed written price
- Guide price from £75 per m² + scaffold, 0% VAT
- Planning and building control checked for Wales
Free survey in South Glamorgan
Tell us the postcode and what you need.
Included as standard
- External insulation keeps room sizes and treats cold bridges well
- Both can be done in stages, elevation by elevation or room by room
- Breathable options for stone and lime-mortared walls
- In England and Wales, Building Regulations apply when more than half of a wall is treated
- Internal insulation suits single rooms or where the outside can't change
What we look for in South Glamorgan
South Wales has long runs of solid-wall valley terraces, Victorian and Edwardian town housing and post-war council estates.
Exposure to wind-driven rain varies across South Glamorgan: 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.
On solid-walled houses in South Glamorgan, the gable or the most weather-exposed wall is often the place to start.
- Nation
- Wales
- Region
- South Wales
- Towns covered
- Cardiff, Barry, Penarth
- Guide price
- From £75 per m² + scaffold · 0% VAT
Planning and building control 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. Your local planning authority has the final word.
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.
How can I tell if my walls are solid?
Measure the wall thickness at a window or door: about 225mm (9 inches) of brick usually means solid, while 260mm or more often means a cavity. On exposed brick, a pattern with bricks laid end-on (headers) every few courses points to solid construction. Stone walls are usually solid regardless of thickness. Age is a strong clue too — most homes built before the 1920s are solid-walled.
Solid wall insulation prices in South Glamorgan
| Item | Guide price | Notes |
|---|---|---|
| External (EWI) | £105–£210 per m²0% VAT | By board and finish |
| Internal (IWI) | £75–£130 per m²0% VAT | Plus making good |
| Survey and written recommendation | Free with a quote |
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
Get a guide price
Try the online quote tool for a ballpark figure.
Book the survey
A visit at a time that suits you.
Agree the quote
Nothing starts until you've signed the written price.
We do the work
Planned around weather, with you kept informed.
Solid wall insulation in South Glamorgan: questions
Is solid wall insulation worth it?
For many solid-walled homes it's one of the biggest single improvements to comfort, because the walls are often the largest heat-loss area. Savings depend on the home and heating, so we don't promise a figure.
Does solid wall insulation cause condensation?
It can if detailed poorly, particularly internally. A condensation risk check for the proposed build-up and careful detailing at joists, reveals and corners avoid it.
Can I do one wall at a time?
Yes. Many owners start with the coldest or most exposed elevation, often a gable end.
Do you cover all of South Glamorgan?
Yes. We survey and quote solid wall insulation across South Glamorgan, including Cardiff, Barry, Penarth.
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.