How much does loft insulation cost in the UK?
Loft insulation costs £900 on average in the UK. Most jobs fall between £300 and £3,000 for the house. Type of job: Top up an existing layer £300 to £700; Full 270mm £700 to £1,400; Boarded or room-in-roof £1,500 to £3,000. Prices reviewed June 2026.
Loft insulation, sometimes called attic insulation, is one of the cheapest ways to cut heating bills. The price depends on whether you are topping up an existing layer or insulating from scratch, and whether the loft is boarded.
Loft insulation cost calculator
Use the calculator to price your loft insulation in 2026. Adjust the options and area for a UK cost range. Nothing is sent anywhere.
Loft insulation cost breakdown
Typical loft insulation costs, by option:
| Type of job | Typical UK cost |
|---|---|
| Top up an existing layer | £300 to £700 |
| Full 270mm, open loft | £700 to £1,400 |
| Boarded or room-in-roof | £1,500 to £3,000 |
| + Insulated loft hatch and ladder | add £150 to £400 |
What's included in the price?
Typical loft insulation prices include:
- Survey and materials
- Insulation laid to the current 270mm depth
- Draught-proofing the loft hatch
- Clearing the working area
What changes the price?
The things that move loft insulation prices most:
Loft size and ease of access
Topping up an existing layer or a full new one
Whether the loft is boarded or used for storage
Hard-to-treat lofts such as room-in-roof or sloping ceilings
How the price is built up
The price is built up from the loft size, the amount of material and the fitter's time, so a simple job stays low. Topping up an existing layer to the full depth is the cheapest work because the old insulation stays put and the fitter just rolls more over it, which is why a top-up runs £300 to £700. A full 270mm layer in an open, empty loft means clearing the space and insulating between and over the joists, landing between £700 and £1,400. Boarding for storage or a room-in-roof costs the most, £1,500 to £3,000, because raised battens and boards or insulating sloping ceilings take far more labour. An insulated hatch and ladder adds £150 to £400. Materials are cheap for this trade, so labour is usually the larger share, often around 60 to 70 percent of a straightforward job, with mineral wool rolls and boards making up the rest. On a boarded loft the labour share climbs higher still.
Ways to keep the cost down
- If you already have some insulation, ask for a top-up to the full 270mm rather than a strip-out and replace. Topping up sits in the £300 to £700 band, well below a full new layer.
- Clear the loft of stored boxes and belongings yourself before the fitter arrives. Access and clearing time is part of the labour, and an empty open loft keeps a full job nearer the £700 end than £1,400.
- Only board the area you actually need for storage. Boarding pushes a job into the £1,500 to £3,000 band, so a couple of boarded metres near the hatch costs far less than boarding the whole floor.
- Check whether you qualify for ECO4 or the Warm Homes: Local Grant before paying. For an eligible household a grant can cover most or all of the cost, which matters more than any quote you compare.
Does where you live change the cost?
In London, loft insulation typically costs around £1,200 for the house, about 30% above the UK average of £900. In the North, Scotland and Wales the guide figure is nearer £830.
| Region | From | Typical | Up to |
|---|---|---|---|
| Midlands / East (UK average) | £300 | £900 | £3,000 |
| London | £390 | £1,200 | £3,900 |
| South East / South West | £350 | £1,000 | £3,400 |
| North / Scotland / Wales | £280 | £830 | £2,800 |
Guide prices for the house, scaled with the same regional multipliers as the calculator. Not quotes.
Loft insulation cost in major UK cities
| City | From | Typical | Up to |
|---|---|---|---|
| Belfast | £260 | £770 | £2,600 |
| Birmingham | £290 | £880 | £2,900 |
| Bristol | £330 | £990 | £3,300 |
| Cardiff | £280 | £850 | £2,800 |
| Edinburgh | £290 | £880 | £2,900 |
| Glasgow | £270 | £810 | £2,700 |
| Leeds | £280 | £840 | £2,800 |
| Liverpool | £280 | £830 | £2,800 |
| London | £390 | £1,200 | £3,900 |
| Manchester | £290 | £860 | £2,900 |
| Newcastle | £270 | £810 | £2,700 |
| Sheffield | £280 | £830 | £2,800 |
City guide estimates, scaled by local labour costs. Indicative averages for loft insulation, not quotes.
Fairly consistent nationally. Grant funding changes what you pay more than location does: ECO4 runs to 31 December 2026, and the Warm Homes: Local Grant is open in England. Either can cover most of the cost for an eligible household.
Common questions
How much does it cost to insulate a loft?
A straightforward 270mm roll-out in an open loft is typically £700 to £1,400. Topping up an existing layer is less, while a boarded or room-in-roof loft costs more.
Are there grants for loft insulation?
Yes, for some households. ECO4 runs until 31 December 2026, and in England the Warm Homes: Local Grant covers privately owned homes with an EPC of D to G where household income is usually £36,000 a year or less. Either can cover part or all of the cost, so check before you pay, as it can make the work free. The Great British Insulation Scheme, which used to be the broader route, closed to new applications and ended on 31 March 2026.
What depth of loft insulation do I need?
The recommended depth for mineral wool is 270mm. Many older homes have 100mm or less, and topping up to the full depth is one of the cheapest effective jobs in home energy: £300 to £700 for a typical house with an open, accessible loft.
Can I insulate a loft myself?
An open, empty loft is a genuinely DIY-able job: rolls for a typical semi cost a few hundred pounds, and the technique is mostly about not compressing the insulation, not blocking eaves ventilation, and keeping it clear of recessed light fittings and cables. Once the loft is boarded for storage or is a room-in-roof, raised loft legs or insulated boards are needed and paying £1,500 to £3,000 for a proper job makes more sense.
Is it worth replacing old loft insulation?
Usually not. If the existing layer is dry and undamaged, topping it up to the full 270mm is the sensible route and costs £300 to £700, far less than a strip-out and full replacement at £700 to £1,400. Old mineral wool keeps working for decades, so you only pull it out if it is damp, mouldy or crushed flat under boarding. Replacing sound insulation just to start fresh is money you do not need to spend.
How much is loft insulation if I buy the materials at B&Q myself?
Materials alone are the cheap part. Mineral wool rolls run roughly £30 to £45 each, and a typical loft needs several, so a DIY top-up in materials often lands near the £300 floor of the top-up band. What you save is the fitter's time, which is the larger share of a professional job. Doing it yourself makes most sense on an open, easy-access loft. A boarded or room-in-roof loft is harder and better left to a fitter.
Do I need to empty and clear my loft before insulation is fitted?
Yes, for a full new layer the loft needs to be clear so the fitter can reach the joists. Clearing it yourself saves money because access and moving belongings is charged as labour, and an empty open loft helps keep a full 270mm job nearer the £700 end of its £700 to £1,400 band. A top-up over existing insulation is less disruptive, but the working area still needs to be reachable.
Is loft insulation worth it for the money?
For an uninsulated or thin loft, yes, this is one of the better-value jobs in the house. A straightforward open loft at £700 to £1,400 pays back through lower heating bills over a few years, and it makes upstairs rooms warmer straight away. A boarded or room-in-roof job at £1,500 to £3,000 takes longer to pay off, so weigh that against how much you use the space.
Official guidance and sources
The rules and schemes referenced on this page come from these official UK sources. The price figures are Costwise's own; see how we price.
- Find energy grants for your home (Help to Heat) GOV.UK · The current list of government insulation and heating grants. The Great British Insulation Scheme ended on 31 March 2026.
- Warm Homes: Local Grant GOV.UK · England only. Covers loft, wall and underfloor insulation for eligible homes rated EPC D to G.
- Energy Company Obligation (ECO4) GOV.UK · Insulation may also be funded under the Energy Company Obligation.
These are independent guide prices based on typical UK jobs in 2026. Your actual cost depends on your property, spec, access and where you live. Always get at least three written quotes before committing.