Solid wall insulation · South Glamorgan
Solid wall insulation in Penarth
If you're planning solid wall insulation in Penarth, start with a free survey: we measure, check the walls and confirm planning and building control for your address. On solid-walled houses in Penarth, the gable or the most weather-exposed wall is often the place to start.
- Free survey in CF64 and nearby
- Guide price from £75 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Penarth
Postcode, service and a phone number is all we need.
What the job covers
- Internal insulation suits single rooms or where the outside can't change
- External insulation keeps room sizes and treats cold bridges well
- Breathable options for stone and lime-mortared walls
- Both can be done in stages, elevation by elevation or room by room
What we look for in Penarth
As well as Penarth itself, we quote in Cardiff, Barry and Caerphilly. It's roughly 3 miles from Penarth to Cardiff, the largest town 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.
For solid-walled homes in Penarth, we check wall thickness and age first to confirm there's no cavity to fill.
- Postcode district
- CF64
- County or area
- South Glamorgan
- Nation
- Wales
- Nearby
- Cardiff, Barry, Caerphilly, Risca
Wales: planning and regulations
For homes in Penarth, the local planning authority decides any borderline cases; changing a brick house to render, or work on flats, usually needs an application in Wales.
In Wales, insulating or re-rendering more than half of a wall's area is treated as renovating a thermal element under Approved Document L (Wales), so 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 Penarth
| 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.
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.
Solid wall insulation in Penarth: 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.
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.
Do you cover Penarth?
Yes — we survey and quote solid wall insulation in Penarth (CF64) and nearby Cardiff, Barry and Caerphilly, with a fixed written price before any work starts.