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How much does spray foam insulation cost?
Eco Spray Foam Insulation installs spray foam in commercial and farm buildings in and around Bristol. Here is what published 2026 UK guides say it costs.
Updated 12 November 2026. Prices are published UK estimates, not a quote from us.
The short answer
UK guides put spray foam insulation at about £20 to £50 per m² for open cell and £40 to £80 per m² for closed cell, including installation (Less.co.uk, 12 November 2026). Those figures are for homes. We install spray foam only in commercial and farm buildings and price each job after seeing the building.
We could not find a published price list for commercial or farm buildings, and the guides we found price homes. The figures below are UK ranges from named 2026 guides, collected on 12 November 2026. They show the usual rates per square metre. Large industrial and farm buildings are priced by the job, so they are not a quote from us or from any other firm.
Spray foam insulation cost per square metre
Less.co.uk (12 November 2026) gives these rates, including professional installation.
| Where the foam goes | Open cell per m² | Closed cell per m² |
|---|---|---|
| Loft or roof | £20 to £35 | £40 to £60 |
| Underfloor | £25 to £40 | £45 to £70 |
| External walls | £30 to £50 | £50 to £80 |
| All applications | £20 to £50 | £40 to £80 |
The Home Owners Alliance (updated 8 October 2026) lists spray foam insulation at about £37 per m² for materials, plus VAT.
Open cell and closed cell
According to Less.co.uk, open cell is typically applied about 100mm thick and closed cell about 50mm thick, and closed cell costs roughly double open cell per m². The price also rises when a BBA certified product is used.
What changes the price
- Area. Pricing is per m², so a larger surface costs more.
- Thickness. More foam costs more.
- Access and preparation. Awkward spaces, clearing and stripping existing insulation add cost.
- Building height. Multi-storey walls may need scaffolding.
- The type of building. Steel, timber and corrugated roofs are sprayed differently from a brick house.
Commercial and farm buildings
We install open cell and closed cell spray foam in offices, warehouses, industrial units, farm buildings and barns, steel and portal frame buildings, timber buildings, corrugated and galvanised roofs, shipping containers, boats and caravans. On metal roofs, spray foam can help with condensation.
We do not spray foam home lofts. If your house already has spray foam in the roof, see our spray foam removal cost guide.
How we price a job
Ask for a price and we will tell you what we need to know: the building type, the roof or wall area, how you reach it and whether you want open or closed cell foam. Prices depend on the building, so we do not publish a single rate.
Common questions
Do you spray foam home lofts?
Is closed cell more expensive than open cell?
Can I do spray foam insulation myself?
Have a commercial or farm building to insulate? Call us for a price.
Call 0117 362 0417 (Monday to Sunday, 9am to 7pm) or use the form below.