Solid wall insulation · Gwent
Solid wall insulation in Caerphilly
Looking for solid wall insulation in Caerphilly? We survey homes across Caerphilly and the CF83 area, then give you a fixed written price before any work starts. On solid-walled houses in Caerphilly, the gable or the most weather-exposed wall is often the place to start.
- Free survey in CF83 and nearby
- Guide price from £75 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Caerphilly
Postcode, service and a phone number is all we need.
What you get
- Breathable options for stone and lime-mortared walls
- In England and Wales, Building Regulations apply when more than half of a wall is treated
- Both can be done in stages, elevation by elevation or room by room
- Internal insulation suits single rooms or where the outside can't change

What we look for in Caerphilly
We also cover Risca and Pontypridd, close to Caerphilly. It's roughly 9 miles from Caerphilly to Newport (Gwent), the largest town in Gwent. 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 Gwent: 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.
For solid-walled homes in Caerphilly, we check wall thickness and age first to confirm there's no cavity to fill.
- Postcode district
- CF83
- County or area
- Gwent
- Nation
- Wales
- Nearby
- Risca, Pontypridd, Cardiff, Newport (Gwent)
Approvals in Wales
For homes in Caerphilly, the local planning authority decides any borderline cases; changing a brick house to render, or work on flats, usually needs an application in Wales.
Welsh Building Regulations expect walls to be upgraded when a substantial area is renewed, and building control signs the work off.
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 Caerphilly
| 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.
What happens next
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 Caerphilly: questions
Can I do one wall at a time?
Yes. Many owners start with the coldest or most exposed elevation, often a gable end.
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.
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.
Do you cover Caerphilly?
Yes — we survey and quote solid wall insulation in Caerphilly (CF83) and nearby Risca, Pontypridd and Cardiff, with a fixed written price before any work starts.