Roughly a fifth of Scotland’s housing stock is solid wall — no cavity, no insulation, and up to a third of the heat going straight out through it. This is the upgrade that makes every other upgrade cheaper to run.
Solar and heat pumps change where your energy comes from. Insulation changes how much you need in the first place — and that saving never degrades, never needs servicing and never goes offline.
The Energy Saving Trust puts the annual saving from external wall insulation at around £150 for a mid-terrace, £280 for a semi-detached and £500 for a detached house. It is not a one-off — it is every year, for as long as you own the house.
Figures: Energy Saving Trust, gas-heated home, July 2026 fuel prices. Your own figure depends on your property and how you heat it — we work it out at survey.
We fix 60–100 mm of insulation board to the outside of your walls, then finish it with a mesh-reinforced basecoat and render. Because the insulation sits outside the masonry, you lose no internal floor space and the walls stay warm — which is what stops condensation forming.
Roughcast is what most Scottish houses wear, and it is the finish we lay most often. We also apply dry dash, monocouche and silicone systems — over insulation or straight onto sound existing walls. Which one suits you depends on the wall behind it, how exposed the property is, and the look you are after. We will tell you at survey which we would put on our own house, and why.
Failed pebbledash, cracked cement render, damp patches and blown areas. We strip back to sound substrate and rebuild the system properly rather than skimming over a problem that will come back in two winters.
Wetherby and Baumit systems, fitted by a manufacturer-accredited installer. Before an insulated system goes on a wall the masonry is pull-out tested and the manufacturer produces a site survey for your property. That paperwork is what a ten-year guarantee on the whole system stands on — and it is handed to you, not filed with us.
EWI is a system, not a product. Every layer does a job, and skipping one is where failures come from.
Existing render assessed and made good, rainwater goods removed, sills and reveals prepared. Anything unsound comes off before we start.
60–100 mm EPS or mineral wool, mechanically fixed and adhesive-bonded. Thickness is set by your wall construction and the U-value we’re targeting, not by a standard spec.
Polymer basecoat with an embedded fibreglass mesh. This is the layer that stops cracking, and it’s the one most often skimped on.
Roughcast, dry dash, monocouche or silicone topcoat in your chosen colour and texture, plus new beads, sills and reveals so the detailing looks deliberate rather than patched.
Mineral wool boards mechanically fixed, then the reinforced basecoat combed out with the fibreglass mesh bedded inside it rather than pressed onto the face. This is the layer nobody sees once the finish goes on — which is exactly why it gets skimped.
Add 90–100 mm of insulation and the existing verge no longer oversails the wall. Here the roofline is extended on new battens with a new fascia fitted, so water still runs clear of the system. Skip this and the water runs down the back of the insulation instead — which is the single most common reason EWI fails in Scotland.
Not an old building — a house of around twenty years. The render had lost its bond across the whole elevation, and after a big storm it started coming away. There was nothing worth patching, so we took all of it off and rebuilt in two coats. July 2024. The dates are the ones the camera recorded.
Roughcast, dry dash and render across Perth, Dundee, Fife and Angus. Our own jobs, our own photos.
BeforeAfter
BeforeAfter
White, cream and beige dash, smooth silicone in colour, roughcast on gables — the finish is chosen to suit the house and the street, not a standard spec.
Nothing about the house changed except how much it costs to live in. If you are planning more than one upgrade, insulation comes first in almost every case: it permanently reduces how much energy the home needs, and it makes the solar sizing decision easier because your demand is stable and predictable.
Book a whole-property survey →A typical semi-detached EWI job runs 2–3 weeks on site, weather depending. Render is temperature-sensitive, so autumn slots are the last of the year.
We check wall construction, existing render condition, damp, and whether planning or a building warrant applies to your property.
Insulation thickness, finish, colour and detailing agreed, with a fixed, itemised price set out in writing.
Scaffold up, system applied layer by layer with proper curing time between coats. We don’t rush render in bad weather.
Rainwater goods refitted, site cleared, and a full handover pack with the system specification and guarantee documents.
Most Scottish properties built before roughly 1930 are solid wall, and many stone-built properties well after that. A quick check is the brick pattern: if you can see short ends appearing regularly in the coursing, it’s likely solid. Wall thickness at a window reveal is another indicator. We confirm it properly at survey — and if you already have cavity walls, we’ll tell you that cavity fill is a far cheaper route than EWI.
Done properly, the opposite. EWI keeps the masonry above dew point, which is what stops interior surface condensation and the mould that follows it. Problems arise when a non-breathable system is put on a solid stone wall that needs to breathe, or when detailing at sills and reveals is done badly. We specify breathable build-ups on traditional construction and we detail the junctions properly — that’s most of the job.
Often not, as EWI on an unlisted house frequently falls under permitted development. It does change the external appearance and wall thickness though, so listed buildings, conservation areas and some flatted properties need consent. A building warrant may also apply. We check your property’s status at survey stage and tell you what’s needed before you commit.
It depends heavily on wall area, access, existing render condition and the finish you choose, so the figure comes from a survey rather than a web page. Whatever the number, it’s worth weighing against the fact that the saving continues for thirty-plus years with no maintenance and no equipment to replace.
Usually yes. Silicone renders come in a wide range of colours and textures, and we can match most existing finishes closely enough that a semi-detached pair still reads as one building. In conservation areas the finish may be specified for you as part of the consent.
Book a free survey. We’ll assess your wall construction, tell you what a proper EWI system would involve, and give you a fixed price — with no obligation and no hard sell.
Free survey. Tell us what the job is — we reply within one working day to book the visit.
