Loft insulation costs

Most UK homes could do with more insulation, but our research shows that the price puts many of us off. Loft insulation though can be quite affordable and easy to fit. Here we look at loft insulation costs in detail, what to avoid, and how you can reduce the price.

Ruth Jackson-Kirby Personal Finance & Property Journalist

Our 2024 HomeOwners Survey revealed that more than a third of us have been put off improving our home’s energy efficiency because of cost. But loft insulation can be the easy win here. Research by the Energy Saving Trust found that a quarter of your home’s heat is lost through the roof in an uninsulated home. Fixing that can cost under £1,000 and save you almost £300 a year. So, you could recoup your loft insulation costs in just over three years making it one of the quickest options for insulating your home and seeing savings in your pocket.

Here’s everything you need to know about loft insulation costs.

How much does loft insulation cost in the UK?

For the average three-bedroom semi-detached home in the UK you can expect your loft insulation cost to be around £900, according to the Energy Saving Trust. That price can rise to £1,100 for a detached house and £1,200 for a detached bungalow.

However, what you’ll pay to insulate your loft will be affected by several factors including:

• The size of your home
• Access and shape of your loft
• The type of insulation you choose
• Whether or not you do it yourself

The table below gives you an idea of the average price for the most common loft insulation costs.

Source: Checkatrade

Loft insulation should help to make your home more energy efficient and save you money on your heating bill. It’s also worth checking whether you can cut your gas and electricity bills if you switch energy suppliers. We’ve partnered with The Energy Shop to provide you with an instant tool to compare energy deals and see how much you can save.

Additional loft insulation costs

Alongside the standard budget you could face additional loft insulation costs if there is other work that needs to be completed for all the insulation to be installed safely and successfully.

Common additional costs include insulating pipework in your loft, relocating electrical wiring and installing loft boarding.

Insulating pipework will cost you between £6 to £35, according to Checkatrade. That includes materials and labour.

Moving electrical wiring can cost £300 a day and loft boarding around £55 per square metre.

Find a reputable local builder. Search “Loft insulation” to find vetted members of the Federation of Master Builders, see reviews and recent projects and ask for a quote.

Can I get free loft insulation?

The government’s Great British Insulation Scheme can help you with your loft insulation costs. You may be able to get free loft insulation or help with the cost depending on the current energy efficiency of your home and your council tax band.

Homeowners, landlords and tenants can get financial support with home insulation covering:

• Cavity wall insulation
• Solid wall insulation
• Loft insulation
• Flat or pitched roof insulation
• Underfloor insulation
• Solid floor insulation
• Park home insulation
• Room-in-roof insulation

You may qualify if your home has an energy performance certificate (EPC) of D to G. You can check your EPC on the government website or if you don’t have one and would like to know the energy rating of your property, you can get an EPC survey undertaken by a local energy assessor.

Your home will also need to be in Council Tax bands A-D in England or A-E in Scotland and Wales. You can check your council tax band at Gov.uk.

If you are eligible your energy supplier will arrange an assessment of the property and let you know what insulation is suitable and if you will need to pay anything towards having it installed. For more information on this and other schemes, see our guide on Energy Grants.

Will loft insulation save me money?

Insulating your loft will cut your energy bills. Over 25% of the heat in your home is lost through an uninsulated loft. Sorting it out can save you almost £400 a year on your bills, according to the Energy Saving Trust.

It estimates that the average mid-terrace house would save £200 a year if 270mm of loft insulation was installed. This rises to £230 for a semi-detached house, £370 for a detached bungalow and £380 for the average detached home.

If you manage to get your loft insulated for free that will be an immediate saving on your bills. If you have to pay for loft insulation you can expect to recoup the costs in around three years depending on your property.

Source: Energy Saving Trust/Checkatrade

For further savings on your energy bill, it’s also worth checking whether you can cut your gas and electricity bills if you switch energy suppliers.

Use our free tool to compare energy deals instantly and see how much you can save.

What are the different types of loft insulation?

The cost of loft insulation will depend on the product you choose to use. There are several different types of loft insulation on the market. The right one for you will depend on your home, what you use your loft for, your budget and how easy it is to access your loft space.

Cost of Blanket insulation

Blanket insulation is the cheapest type of loft insulation. Sold by the roll it is made from sheep’s wool, mineral wool or fibreglass. It costs around £10 per square metre. The attraction of blanket insulation is the low cost and that it can be an easy DIY option, but it can be quite bulky so difficult to install in small spaces.

Cost of loose-fill insulation

Loose-fill insulation is an environmentally friendly option for loft insulation as it can be made from recycled cork granules (or mineral wool or cellulose fibre). However, it must be professionally installed as it needs specialist safety equipment to protect the installer from skin irritation. You can expect to pay around £12 per square meter for loose-fill insulation.

Cost of sheet or foam board insulation

Sheet or foam board insulation is made from PIR (polyisocyanurate) and is often used in loft conversions as you can slot it between the rafters in sloping spaces. However, it costs a lot more than blanket or loose-full insulation at around £35 per square metre.

Cost of spray foam insulation

Spray foam – or blown-foam insulation – is where a machine is used to spray insulating foam into an area. It is often used where loft access is tricky. It must be professionally installed which means the cost of spray foam insulation is higher than other options. You can expect to pay an average of £37 per square metre.

However, there can be serious problems with spray foam insulation. It can cause condensation which can cause problems with untreated timbers. It is also difficult to remove. Mortgage lenders and equity release firms often have issues lending on properties with spray foam insulation as it makes it difficult for surveyors to inspect the loft and roof. The HomeOwners Alliance advise against installing spray foam roof insulation at this time.

Cost of thermal foil layer insulation

Thermal foil layer insulation is a type of insulation sold in rolls made up of layers of foil and insulating materials. It is one of the thinnest loft insulation options so could be an option if space is tight. Thermal foil layer insulation costs around £14 per square metre.

Find a reputable local builder to help with your loft insulation project:

What factors affect the loft insulation cost?

How much your loft insulation will cost will be affected by several factors – no two lofts are the same after all. Whether it is existing insulation, a complex space or paying a professional, all these things will impact the overall cost of insulating your loft.

• What you use your loft for: Insulating a loft that is only used for storage is likely to be substantially cheaper than insulating a loft that is used as a room. The former can be insulated with cold loft insulation laid across the floor. But if you use your loft for living space, you’ll need warm loft insulation where the insulation is placed in the rafters and walls.
• If you already have insulation: Many of us already have some loft insulation but it may fall below the government-recommended thickness of 270mm. If it is still in good condition and dry you can save money by simply adding more insulation on top to increase the thickness.
• Loft problems: If you have damp in your loft or draughts you will need to pay to get these issues resolved before you insulate. Otherwise, your insulation could be damaged, or you could end up with rot or mould that cause much bigger problems.
• Install it yourself or pay a professional: Having your loft professionally insulated could cost you two to three times more than doing it yourself. But only embark on a DIY job if you are confident, you can do it well. Make mistakes and you could end up with a costly repair bill that eliminates those initial savings.

Cold loft insulation vs warm loft insulation

Cold loft insulation is the most common type of insulation used in lofts. It essentially means the insulation is laid across the floor of the loft, so it insulates your home, so no heat is escaping into your loft and beyond – so your loft is still cold.

Warm loft insulation is where the insulating products are fitted around the walls and roof in your loft, so your home and loft are insulated – giving you a warm loft. This could be a good option if you want to be able to regulate the temperature in your loft. Either because you are storing important items up there – not just the Christmas decorations – or you use your loft space as living space.

The drawback with warm loft insulation is it is more expensive than cold loft insulation and there is an increased chance of causing condensation problems. You may not see as bigger reduction in your energy bills with warm loft insulation either. That’s because heat will still escape from your home into your loft meaning your heating system will have to work a bit harder to keep your home warm.

Damp and leaks impact on loft insulation costs

If you have damp problems or leaks in your home, you must solve these problems before installing loft insulation. That’s because the insulation in your loft is great at keeping the heat in your home, but it can also trap moisture.

A professional can help you draughtproof your loft and ensure it is properly ventilated to ensure your insulation improves your home rather than causing more problems.

There are plenty of ways to help improve ventilation and protect your home from damp in the loft space. These include:

• Fitting a chimney pot cover
• Draught-proofing and insulating your loft hatch
• Filling gaps where pipes go through walls and floors with foam or paste.
• Installing an extractor fan in your loft if you are going to opt for a cold loft insulation.
• Filling small cracks in your walls and ceilings.

Find a reputable local builder. Search “Loft insulation” to find vetted members of the Federation of Master Builders, see reviews and recent projects and ask for a quote.

How to reduce loft insulation costs

You can reduce your loft insulation costs by considering your budget when choosing the type of insulation, you want to use and opting to do the job yourself. However, consider the quality of the insulation you choose as spending a little more could save you in the long run if it is more energy efficient and therefore likely to reduce your energy bills by more than the cheapest option.

Also, getting your loft insulation professionally installed may cost you more initially but it could prevent you from experiencing costly problems in the future.

You can still reduce your loft insulation costs even if you use a professional by getting several quotes and shopping around for the best deal. It is also a good idea to ensure your loft is easily accessible and clear of clutter so the job can be done with minimal fuss and cost.

You may also be able to cut the cost of loft insulation through the government’s Great British Insulation Scheme. If your home qualifies you may get free loft insulation or a discount.

What is the cheapest way to insulate your loft?

The cheapest way to insulate your loft is to opt for DIY cold loft insulation. Rolling out blanket insulation between the joists in your loft is a relatively uncomplicated job. Just make sure you know what you are doing.

The government recommends you lay at least a 270mm thickness layer or insulation and you leave a 50mm air gap between the insulation and your floorboards to minimise condensation.

When it’s laid, you are likely to need to create a new floor to ensure you don’t squash the insulation or place boards over the top if you are using the space just for storage.

If you do opt to do the job yourself, make sure you wear protective gear including gloves, googles and a mask as some loft insulating materials can be irritants.

While a DIY job can be the cheapest option make sure any problems in your loft such as damp or draughts have been dealt with first and you are confident doing the job. Get it wrong and what you save can be eradicated by sorting out any future problems.

What does it cost to remove old loft insulation?

If you have existing loft insulation that has become damp, compressed or generally is in a poor state of repair you may want to remove it before you install new loft insulation. It is a fairly straightforward job to remove blanket insulation, but it requires a lot of lugging insulation around. You can expect to pay around £250 for a day’s labour plus the cost of skip hire or a waste removal company.

Spray foam insulation is the most expensive to remove and will require a professional but also comes with other risks so should really be seen as a last resort option. According to Checkatrade the cost of removing spray foam insulation is around £40 per square metre. You will also need to budget for the safe disposal of the insulation. But before removing spray foam insulation read our guide. There have been a number of cases of dodgy cold-callers removing the foam and charging astronomical amounts for doing so. During removal, even by a legitimate firm, there is a risk of causing damage to timbers and the roof.

Can I insulate my loft myself?

If you opt for blanket or foil insulation you may be able to install it yourself.

Getting your loft insulation fitted professionally will ensure the job is done properly and any problems that could affect your insulation will be identified and dealt with.

Before you embark on a DIY loft insulation project be aware that poorly installed insulation can cause problems that ultimately could affect the structure of your home. For example, if your loft insulation causes condensation it could lead to your roof timbers rotting.

Get the experts in. Simply click here, search for “Loft insulation” to find professionally vetted members of the Federation of Master Builders near you, to help with your project.

Frequently Asked Questions