Comprehensive guides to insulating your UK home. Cavity wall, loft, external wall, and underfloor insulation costs, savings, and DIY vs professional installation.
209 articles
Insulating a bay window costs £50 to £1,200. The cheapest option is thermal curtains (£50-£200), which can reduce heat loss by up to 25%. For better insulation, secondary glazing or…
Insulating a stone wall cottage costs £4,000-£18,000 for internal insulation. You must use breathable materials like wood fibre or hempcrete to avoid damp. Standard cavity insulation does not apply to…
Garage conversion insulation must meet U-values of 0.18 W/m²K for walls and floors, and 0.13 W/m²K for roofs under Building Regulations (2026). Insulate all six sides and notify building control…
Spray foam insulation costs £2,500 to £6,500 for a typical 3-bed semi-detached house in 2026. Closed-cell foam is more expensive but achieves lower U-values in thinner layers, making it suitable…
A warm roof is the standard for a habitable dormer attic room. Insulate the roof slopes, vertical dormer walls and floor to a U-value of 0.16 W/m²K using rigid PIR…
Insulating a pitched roof from inside costs £8–£35 per m², or £400–£1,750 for a standard 50 m² roof including labour. Between-rafters insulation is cheaper but less effective at stopping heat…
Caravan insulation costs £600-£2,500 in the UK for materials and DIY labour. The price depends on caravan size and material, with closed-cell foam offering the best value for money. Compare…
Insulating a loft hatch properly can cut up to 5% of home heat loss, based on a 2023 DESNZ report. Use rigid PIR board at least 50mm thick plus a…
Before heating a lean-to conservatory, upgrade the roof insulation, polycarbonate panels lose heat ten times faster than a standard wall. A solid insulated roof replacement costs £3,500 to £7,500 and…
A porch creates a thermal airlock at your front entrance, reducing cold air infiltration each time the door opens. In 2026, a fully enclosed double-glazed porch costs around £3,000 to…
To check whether your home already has cavity wall insulation, search the free CIGA database at ciga.co.uk using your postcode, then download your property's Energy Performance Certificate from the gov.uk…
Internal wall insulation for period properties involves fixing insulating boards or natural materials to the inside face of solid brick or stone walls, preserving the exterior appearance while reducing heat…
Underfloor insulation for a suspended timber floor involves fitting insulating material, most commonly mineral wool batts or rigid foam boards, between the timber joists in the void beneath your ground…
Insulating a solid wall house internally is a highly effective way to cut heat loss in older UK properties, where uninsulated solid walls can account for up to 35% of…
External wall insulation in the UK costs between £80 and £200 per square metre installed in 2026, with whole-house projects typically ranging from £8,000 to £25,000 depending on property size,…
The recommended loft insulation thickness in the UK is 270mm of mineral wool for a standard cold loft, as specified under Part L of the Building Regulations and endorsed by…
UK home insulation costs range from £300-£500 for loft insulation saving £200-£300 per year, to £500-£1,500 for cavity wall insulation saving £200-£400 per year. The Great British Insulation Scheme closed…
Cavity wall insulation typically costs 500 to 1,500 pounds for a standard three-bedroom semi-detached house. The exact cost depends on the size of your home and accessibility. It can save around 150 to 250 pounds per year on heating bills, giving a payback of 3 to 6 years.
The recommended thickness for loft insulation in the UK is 270mm of mineral wool or equivalent. Many older homes have only 100mm or less. Topping up existing insulation to the recommended depth is one of the cheapest and most effective energy improvements you can make.
External wall insulation costs 8,000 to 15,000 pounds but can save 200 to 400 pounds per year on heating bills. It also improves comfort, reduces condensation risk, and can transform the appearance of your home. Grants through ECO4 or the Great British Insulation Scheme may cover part of the cost.
You can DIY loft insulation and basic draught proofing, which are straightforward projects. However, cavity wall insulation, external wall insulation, and underfloor insulation should be installed by certified professionals to ensure effectiveness, building regulations compliance, and warranty coverage.
Check your EPC certificate which will state whether cavity wall insulation is present. For a physical check, a professional can drill a small hole in the wall and use a borescope to inspect the cavity. Homes built after 1990 are likely to have insulation fitted during construction.
Insulating a brick wall from inside costs £40-£80/m² and cuts heat loss by up to 45%. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures…
Silicone render costs £45-£60 per square metre installed for external wall insulation. It is the most breathable and self-cleaning finish, reducing long-term maintenance. Compare render types now.
Insulating a garage roof costs £300–£800 for materials on a single-car garage. This is one of the cheapest ways to cut heat loss from an attached garage, according to the…
Insulating a suspended timber floor costs £500–£1,200 for a typical UK semi-detached home. Annual heating bill savings range from £40–£80 (Energy Saving Trust, 2026).
Internal wall insulation typically needs 60–120 mm thickness to meet Building Regulations U-values. Solid brick walls require 80–100 mm, cavity walls 60–80 mm, and solid stone walls 100–120 mm. Thicker…
The maximum solid wall insulation grant in 2026 is £7,500 under ECO4, but most households will not receive this full amount. Eligibility depends on income, property type, and energy performance,…
