Up to 35% of your home's heat escapes through uninsulated walls every single day. Cavity wall insulation stops that — in one day, from outside your home, with no mess inside.
Most UK homes built before 2000 have cavity walls that were never insulated. That gap between your inner and outer wall is letting warmth — and money — escape constantly.
Walls are the single biggest source of heat loss. And unlike roofs or windows, cavity wall insulation is typically the most cost-effective fix — with payback in 3–5 years and a 25-year guarantee.
Cavity wall insulation doesn't just save you money. Here is the full picture of what gets better the day after installation.
Stop paying to heat the outdoors. Most households save £250–£400 every year — from the very first heating season.
Walls that were cold to the touch become noticeably warmer. Rooms reach temperature faster and hold it longer.
Most properties improve by 1–2 EPC bands. For landlords, that often means the difference between compliant and non-compliant.
A certified energy improvement shows up in valuations and attracts more buyers. It's a permanent, documented upgrade.
Cut your home's CO₂ output by over 560kg a year on average. A genuine environmental benefit with no ongoing effort required.
Insulation works both ways. The same material that keeps heat in during winter keeps it out in summer — comfortable all year.
Anyone can drill holes and inject insulation. What matters is the certification behind it, the experience carrying it out, and the guarantee backing it up.
No lengthy process, no uncertainty. Here is exactly what happens after you submit your details.
Fill in the form above. Takes 60 seconds. No obligation.
60 secondsOur installation team calls you within 24 hours to discuss your property.
Within 24 hrsA certified surveyor visits and confirms suitability. No cost, no commitment.
~30 minutesWork done entirely from outside. No mess, no disruption. Typically one day.
1 dayYou receive your PAS 2035 certificate and 25-year CIGA guarantee on the day.
25-year guaranteeGenuine feedback from homeowners and landlords who've had installations carried out through CavityTherm UK.
"Our house always felt cold in the winter no matter how much we had the heating on. After getting cavity wall insulation installed, the difference was really noticeable. The walls don't feel cold anymore and the house warms up much quicker. We're already seeing lower heating usage."
"The process was quicker than we expected and there was very little disruption. Since having it done, the house keeps heat much better and we've definitely noticed a drop in how often the heating needs to be on. Very pleased."
"Some rooms were always colder than others. After installing cavity wall insulation, the temperature feels much more even throughout the house. It's made a big difference to comfort, especially during colder evenings."
Cavity wall insulation is one of the most cost-effective home improvements you can make. Here is the typical picture for a semi-detached home.
Figures are indicative for a typical semi-detached house. Actual costs and savings depend on property size, construction, current EPC rating, and energy tariff. A free survey will give you a personalised assessment.
The free survey gives you exact figures — no estimates, no guesswork. A certified surveyor visits your property and tells you precisely what to expect.
Book My Free SurveyYour free survey costs nothing. There is no obligation to proceed. If your property isn't suitable, we'll tell you straight away. The only thing you have to lose is the heat you're already paying for.