- External Wall Insulation
- Edinburgh
External wall insulation on a new-build home
Insulation boards and basecoat on a new-build blockwork home in Edinburgh.
View project →External Wall Insulation Installers in Central Scotland
Around a third of the heat in an uninsulated home escapes through the walls. External wall insulation (EWI) wraps your property in a thermal jacket — rigid insulation boards fixed to the outside walls, finished with a tough decorative render — cutting energy bills, eliminating cold spots and condensation, and giving your home a complete facelift in one project. AG Rendering Ltd installs complete insulated render systems across Edinburgh, Glasgow, Perth and Dundee.
How External Wall Insulation Works
Insulation boards — typically EPS (expanded polystyrene) or mineral wool such as Rockwool — are mechanically fixed and bonded to your external walls. A reinforced base coat with alkali-resistant mesh goes over the boards, followed by a through-coloured silicone or dash finish. The system moves the "cold line" outside your wall structure, so the masonry stays warm and dry, condensation and mould disappear, and your heating works far less hard.
Benefits of EWI
- Cut wall heat loss by up to 35% and reduce heating bills year after year
- Warmer rooms, no cold internal walls, reduced condensation and mould
- A brand-new exterior finish — smooth coloured render or roughcast dash — with no loss of interior space
- Improved EPC rating, adding value and saleability
- Ideal for solid wall homes that can't take cavity insulation — common across central Scotland
EWI Over Pebble Dash and Roughcast
One of the most common questions we're asked: can you install external wall insulation over pebble dash? Yes — existing dash is assessed, any loose material removed or levelled, and the insulation system fixed through to the substrate. It's one of the most effective upgrades for Scotland's older roughcast housing stock, and the finished system can be dashed again or given a modern smooth coloured finish. More in our EWI cost guide.
Which System Is Right for Your Home?
There's no single right answer — EPS systems offer excellent value and thermal performance; mineral wool adds breathability and fire performance, often preferred for older solid-wall and traditional properties. We survey your home, explain the options plainly, and quote for the system that actually suits your walls, not the one with the biggest margin.
Book a free EWI survey — call 0730 939 0246.
External Wall Insulation projects
Frequently Asked Questions
- How much does external wall insulation cost?
- Most homes fall between £8,000 and £15,000 fitted. Full breakdown: EWI cost guide.
- Is there funding for external wall insulation?
- Grant schemes come and go (ECO, Home Energy Scotland loans). We'll advise what's current when we quote.
- Does EWI need planning permission?
- Usually not for most homes, but conservation areas and listed buildings have restrictions. We'll flag this at survey.
- How long does installation take?
- A typical semi takes 1–2 weeks depending on weather and access.
Book a free EWI survey
Call 0730 939 0246 to arrange a free external wall insulation survey.