Loft insulation cost: what the job involves and who is registered to do it
Loft insulation is the cheapest worthwhile energy measure in most British houses, and its price is driven by three things: the area of the loft, whether there is anything already up there, and what has to be moved out of the way. Topping up from a shallow depth to the current standard is a straightforward job. Clearing decades of storage, lifting old boarding, dealing with a loft conversion above or with downlights below is what turns it into a bigger one.
For context: 569 roofing contractors are registered to certify their own work under the Building Regulations in England and Wales.
- 569 licensed companiesfrom official state registers
- NFRC Competent Person Scheme contractor search (read 2026-09-09)checked 2026-09-09
- 569 registered contractorsNFRC Competent Person Scheme, read 2026-09-09
the UK roofing register
How insulation works
- Measure what is already there. Existing insulation is measured in depth rather than presence, and topping up an old shallow layer is usually cheaper than starting from nothing. A survey that does not report the current depth has not measured the job.
- Decide between the ceiling and the roof line. Insulating at the ceiling is cheaper and makes the loft cold, which suits storage. Insulating at the rafters keeps the loft warm and is what a converted or partly used loft needs. They are different jobs at different prices.
- Deal with the obstacles honestly. Boarded floors, water tanks, cables, downlights that must not be covered, and a loft full of belongings all add labour. These are the lines that separate two quotes for identical roofs.
- Keep the ventilation. Insulation stuffed into the eaves blocks the airflow a cold loft needs and produces condensation and, in time, timber decay. Eaves ventilation trays are a small item that must be in the specification.
- Check whether a scheme will pay for it. Government backed schemes fund insulation for qualifying households, and the qualifying rules change. Check the current scheme before paying, because a job started outside a scheme is rarely brought inside it afterwards.
Insurance and paperwork
Sources
Common questions
- How deep should loft insulation be?
- Current practice is far deeper than most older houses have, and the standard is set in the building regulations rather than by a supplier. Ask the installer what depth they are working to and why.
- Can I insulate a loft I use for storage?
- Yes, with a raised boarded floor over the insulation so it is not squashed. Laying boards directly onto insulation compresses it and removes much of the benefit you paid for.
- Is spray foam insulation a problem when selling?
- Some lenders and surveyors treat spray foam applied to a roof structure with caution, particularly where it conceals the timber. It is worth asking what has been applied and whether documentation exists before assuming it is neutral.
Get insulation quotes
Registered contractors by region
- Registered roofers in the East Midlands postcode area
- Registered roofers in the East of England postcode area
- Registered roofers in the London postcode area
- Registered roofers in the North East postcode area
- Registered roofers in the North West postcode area
- Registered roofers in the Scotland postcode area
- Registered roofers in the South East postcode area
- Registered roofers in the South West postcode area
- Registered roofers in the Wales postcode area
- Registered roofers in the West Midlands postcode area
- Registered roofers in the Yorkshire and The Humber postcode area
Cite or embed this figure
The registered roofing contractors that may self-certify their own work in England and Wales was 569 in September 2026, across 569 registered roofing contractors recorded in the NFRC Competent Person Scheme register.
Cite as: "Roofing Quotes UK Roofing Register", updated 2026-09-09, https://roofingquotesuk.com/insulation/.