Cardiff, South Glamorgan
External Wall Insulation in Cardiff
EWI systems that insulate solid walls externally and finish them in a warranted render topcoat.
We carry out external wall insulation across Cardiff and the surrounding South Glamorgan area throughout the year.
Most of what we see around Cardiff reflects the wider South Glamorgan pattern — Victorian and Edwardian terraces, Cardiff suburban housing and coastal properties, and solid-wall terrace damp and coastal weathering at Barry and Penarth.
Local conditions bring wet with coastal exposure along the Severn estuary, and that has a direct bearing on which systems are worth specifying. Cardiff's victorian terraces are largely solid-wall, and external insulation with a breathable render is the upgrade that suits them best.
When external wall insulation is the right call. Choose EWI on solid-wall, no-fines or non-traditional construction where you want a genuine thermal upgrade rather than just a new finish.
Guide price in Cardiff
| Guide price | £135–£210 per m² |
|---|---|
| Applied thickness | 50-150mm insulation plus render system |
| Guarantee | 25 years |
Indicative only. The guide-price tool gives a range for your property; the survey gives the fixed price.
What the job includes
- EPS, mineral wool and phenolic boards
- 50mm to 150mm thicknesses
- Mechanical and adhesive fixing
- Reinforced basecoat with mesh
- Silicone or acrylic topcoat
- Window and door reveal detailing
If a cheaper specification would do the job, we will say so. If it would not, we will tell you why.
Also covering near Cardiff
External Wall Insulation in Cardiff
Tell us about the property and we will call you back to arrange a survey.
What happens next
Four steps from enquiry to finished wall
Free survey
We visit, test the substrate, measure up and identify what caused any existing failure.
Written quote
An itemised fixed price with the system named, materials specified and scaffold included.
Booked in
An agreed start date, scaffold arranged, and a clear run of days set aside for your job.
Finished and guaranteed
Site cleared, scaffold struck, guarantee documents and system warranty issued.
FAQs
External Wall Insulation in Cardiff
What time of year is best for rendering?
Spring through autumn is ideal. Render should not be applied in frost or in very hot direct sun, so winter work needs protection and settled conditions.
Can you render over existing render?
Sometimes, if the existing coat is completely sound and well-bonded. We hammer-test it first. Anything hollow has to come off, because covering failure just hides it.
Are you insured?
Yes — full public liability cover, and we can send the certificate before we start. We are happy to provide RAMS for commercial and contractor work.
What areas do you cover?
We work UK-wide, with teams across England, Scotland, Wales and Northern Ireland. If we are not the right firm for your location we will tell you rather than waste your time.
How much does external wall insulation save?
On a typical uninsulated solid-wall semi it commonly cuts wall heat loss substantially and makes the biggest single difference to comfort. Actual savings depend on the existing construction, heating system and how you use the house.
Free survey in Cardiff
We will confirm whether external wall insulation suits your walls before quoting a price.