External Wall Insulation in Swindon
House rendering, K Rend & external wall insulation specialists. Free surveys, fixed written quotes, tidy workmanship.
Swindon Rendering installs external wall insulation (EWI) systems across Swindon and Wiltshire — insulation boards fixed to the outside of your walls, finished with a reinforced, through-coloured render. One job does two things: it wraps the house in a thermal jacket, and it replaces a tired exterior with a clean modern finish.
EWI makes most sense on solid-wall homes — the pre-1930s properties around Old Town and Gorse Hill that can't take cavity insulation — and on any house already facing a re-render, where the insulation step adds far less than it would as a standalone project.
How an EWI system is built up
Insulation boards
EPS (expanded polystyrene) is the cost-effective default; mineral wool where breathability or fire classification drives the choice. Typically 90–110mm.
Mechanical fixing & adhesive
Boards are bonded and mechanically pinned to the substrate, with starter tracks at the base and beads at every edge and opening.
Reinforced basecoat
A polymer basecoat with alkali-resistant mesh embedded across the whole surface — the layer that gives the system its impact strength.
Silicone finish coat
A through-coloured thin-coat silicone render in your chosen colour — the same low-maintenance finish as our standard silicone systems.
What EWI saves
Around a third of the heat lost from an uninsulated solid-wall home goes through the walls. Bringing those walls from a U-value of roughly 2.0 down to around 0.3 W/m²K typically saves a three-bed semi several hundred pounds a year at current energy prices — and the difference in comfort is immediate: warmer rooms in winter, cooler in summer, and far less condensation and mould risk on cold internal wall surfaces.
It also lifts the property's EPC rating, which increasingly matters at sale and remortgage time.
External wall insulation cost in Swindon
Grant schemes for insulation come and go — ECO4 and the Great British Insulation Scheme have covered EWI for qualifying households. We'll tell you at survey whether current schemes fit your situation rather than promising funding that may not apply.
| Property type | Typical price range | Notes |
|---|---|---|
| 3-bed semi, full EWI | £8,500 – £14,000 | EPS system, silicone finish |
| 4-bed detached | £13,000 – £20,000 | EPS system, silicone finish |
| Added to a pebbledash removal job | +£3,500 – £6,000 | Marginal cost while walls are stripped and scaffold is up |
Guide prices installed, including scaffold. Detailing (window reveals, soffit lines, drainage) affects the figure — the free survey prices it exactly.
The details that make EWI last
EWI fails at the details, not the flat walls: window reveals need insulating and re-sealing, sills need extending, the base of the system needs a drip track above the damp course, and roofline overhangs have to accommodate the extra 100mm of wall depth. Systems installed to PAS 2030-style standards with certified components avoid the failures that gave early EWI a mixed reputation. We survey all of this before quoting — if a house isn't a good EWI candidate, we'll say so and quote a standard re-render instead.
Frequently asked questions
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Call 01793 569534