Reduce heating bills · Cold wall solution
Reduce heating bills. Fix cold external walls. In one 3–6 mm coat.
Walls are the biggest single source of heat loss in most UK homes — bigger than the roof, windows or floor. Sprayed cork insulation closes that gap with a 3–6 mm coating that pays for itself in lower bills.
Where the heat goes
Walls leak more heat than any other part of your home.
In a typical UK semi-detached property, around 35% of total heat loss goes straight through the walls. Lofts, windows and floors all matter — but if your walls are bare brick, blockwork, sand-and-cement render or single-skin, you're heating the outside more than the inside.
The fastest way to reduce heating bills is to fix the biggest leak first. Sprayed cork adds an insulating skin to the wall in a single 3–6 mm pass, cutting heat loss through that surface by up to 30%.
Cold wall solution
Fix cold external walls without losing a single room.
A cold wall solution has to do three things: warm the internal surface, stop external rain ingress, and not eat your floor space. Traditional internal wall insulation (IWI) fails the third — it takes 80–100 mm off every external wall in the house. Traditional EWI fails the first cost test — £8k–£22k of scaffolding, mesh and render.
Sprayed cork solves all three. It's applied to the outside of the wall in 3–6 mm — invisible from the street, no lost internal space, no skips, no scaffolding scars — and it carries a 25-year warranty. That's how we fix cold external walls on solid, cavity, render, timber and uPVC substrates.
What you'll save
Typical savings on UK home types.
Semi-detached (3-bed, gas central heating): ~£350–£500/yr off the annual heating bill. ~£12,000 saved over the 25-year warranty.
Detached or solid-wall Victorian terrace: ~£500–£900/yr off the annual heating bill. Often combined with an EPC banding uplift that lifts resale value materially.
Why cork pays back faster
Lower bills, warmer rooms, no compromises.
Up to 30% less heat loss
Independently tested U-value uplift on solid-wall and cavity-wall substrates.
£350–£900/yr saved
Typical annual savings at current UK price-cap rates, depending on property size and wall type.
6–10 yr payback
Pays back on bills alone — before counting EPC uplift, damp remediation avoided, or resale value.
Warmer rooms, faster
Warm internal wall surfaces mean rooms reach temperature quicker and your boiler cycles less.
Boiler runs less
Less heat lost through walls = shorter heating cycles, less wear, lower service costs over the system's life.
Cooler in summer too
Cork's closed-cell structure also reduces solar gain — measurably cooler south- and west-facing rooms.
Heating bills & cold walls
Reduce heating bills, fix cold walls — common questions.
- How much can wall insulation reduce heating bills?
- On a typical UK semi-detached home, walls account for around 35% of total heat loss. Adding sprayed cork insulation cuts that loss by up to 30%, which usually translates to £350–£600 off the annual gas bill at current price-cap rates. Larger detached or solid-wall homes typically save more.
- What is the payback period?
- Most installations pay back in 6–10 years on bills alone, before factoring in the value uplift to the property (typically a one-banding EPC improvement) and the avoided cost of damp or mould remediation.
- How do I fix cold external walls?
- Cold external walls are caused by heat conducting straight through uninsulated brick or block. The fix is to break that thermal bridge — either with bulky traditional external wall insulation (EWI), or with a 3–6 mm sprayed cork coating that adds the same insulating layer without scaffolding scars, planning issues or lost detail.
- What's the best cold wall solution if I can't fit internal boards?
- Sprayed cork is the most space-efficient cold-wall solution: it goes on the outside of the wall in 3–6 mm, so you lose zero internal floor space. For listed or restricted exteriors, the same cork system can be applied internally instead.
- Will it help in summer too?
- Yes. Cork's closed-cell structure and pale colour options reflect solar gain, so south- and west-facing rooms stay measurably cooler in summer heatwaves — particularly relevant under Part O overheating regs.
- Are there grants for this work?
- Cork insulation can be eligible under ECO4 and Great British Insulation Scheme funding where the household qualifies and the installer is PAS-approved. We'll flag eligibility during the survey.