Loft Insulation Costs

✔ There are four main types of loft insulation, with blown fibre being the priciest

✔ Loft installation generally takes less than a day to install

✔ Loft insulation should pay itself off within two years, through savings on bills

Effective loft insulation can save you a lot of money on your household energy bills. Measures such spray foam insulation cost £20-£50 per square metre, but it's not the only solution out there.

Regardless of what type you choose, a bonus is that insulation generally pays for itself after about two years.

Here, we explain the main factors involved and what you need to consider.

If you’re interested in adding spray foam insulation to your loft, just enter a few details here and we will put you in touch with expert installers who will be able to provide more detailed advice.

Someone stood in a light loft with windows installing roof insulation panels

What's on this page?

01 How much does loft insulation cost?
02 How much money will loft insulation save you?
03 Are there any government grants for loft insulation?
04 How long does loft insulation take?
05 FAQs

How much does loft insulation cost?

House size	Blanket insulation	Loose fill insulation	Sheet insulation	Blown fibre insulation	Labour costs	Time required
Terraced	£125–£160	£180–£225	£250–£310	£1,375–£1,720	£150–£400 per day	3–4 hours
Semi-detached	£200–£250	£290–£360	£400–£500	£2,200–£2,750	£150–£400 per day	3–4 hours
Detached	£300–£375	£430–£540	£600–£750	£3,300–£4,125	£150–£400 per day	4–6 hours
Bungalow	£375–£420	£700–£730	£1,000–£1,200	Around £3,588	£150–£400 per day	4–6 hours

The cost of installing loft insulation can vary extensively, depending on the size of your house and the type of loft insulation you install.

There are four types of materials you can use, which can impact insulation costs dramatically. The other main factor is the amount of roof space you have in the loft.

The average labour costs are between £150 and £300, but they may be even more for blown fibre installation because of the type of specialist equipment that is used.

What factors affect the cost of loft insulation?

The two main factors are the type of insulation and the amount of roof space to cover.

There are a variety of other factors which may affect the cost of installation. Ease of access, removal of the existing insulation, moving electrical wiring and whether or not a loft hatch or ladder needs to be installed are some of these.

If you wish to use the loft for storage, this will require the laying of boards on top of the joists. However, since the boards can’t be laid on top of the insulation material (because they compress it), the boards will need to have a built-in insulation layer.

A further factor to consider is that since insulation keeps the heat in the rest of the house below the loft, the loft itself will be fairly cold and that means any pipes running through the loft will also have to be insulated. Re-routing wires will require an electrician, again adding to the cost. Leaky roofs will also have to be repaired before the installation of the insulation material.

Additionally, some mortgage lenders will not lend on houses with spray foam insulation, as there is a danger of this material causing condensation and restricting the airflow. This in turn may weaken the roof supports or rot them.

Tips for reducing the cost of loft insulation

One of the best ways of reducing the cost is to shop around, gathering a number of quotes before you decide which installer to use. Comparing quotes could save you up to 40% on the final cost.

Want to learn more about loft insulation? Head to our page: The Ultimate Guide to Loft and Roof Insulation.

How much money will loft insulation save you?

Loft insulation will bring financial benefits within about two years of installation. The Energy Saving Trust estimates that loft insulation can save you about £150 per year, as well as adding 16% to the value of the house.

You can find out more about savings on our Home Insulation Costs page.

Installer dressed in white overalls sits down to install spray foam insulation in a hard-to-reach area

The different types of loft insulation

There are four main types of loft insulation – blanket insulation, loose fill insulation, sheet insulation and blown fibre insulation.

Of these, blown fibre insulation tends to be the most expensive. The insulation should be at least 270 mm thick, whatever the material used, which may be made from fibreglass, mineral wool, sheep’s wool, cellulose or various other materials.

Blanket insulation is the easiest to install and for that reason is suitable for DIY projects. It’s usually available in rolls costing £20 each. These can simply be rolled out between and over the roof joists. Each roll generally covers around 8 m². However, some of the materials involved are skin irritants, so it is advisable to wear protective clothing and gloves. An exception is sheep’s wool, but it tends to be more expensive. Blanket insulation can also be difficult to lay in tight spaces.

Loose fill insulation is a good way of filling in small gaps between the roof joists. It is also a good way of adding to existing insulation. However, the material can come loose in draughty lofts and it requires protective clothing to install.

Sheet insulation consists of firm boards used for insulating the underside of the roof. They are made from

either synthetic or natural materials and are highly effective. They can also be painted over if you want to

decorate the loft space. However, as with blown fibre insulation, sheet insulation does tend to be more expensive.

Blown fibre insulation consists of a layer of material that is sprayed from specialist machinery. This means it can be installed quickly by professional installers. It is an ideal material for tight spaces and it is light and easy to handle. However, professional installers will add to the cost (at least £400). It is also not suitable for draughty lofts.

Which type of loft insulation is right for you?

If the loft is easy to access and there are no pipes or wires running through it, installing loft insulation should be relatively easy and cheap, using rolls of blanket insulation, without the need to call in a professional.

If the loft is not particularly easy to access and there are tight spaces within it, blown fibre insulation may be the better option, but this is expensive and needs a professional to install it.

Are there any government grants for loft insulation?

The main government grant for loft insulation is the Energy Company Obligation (ECO) scheme. This requires energy suppliers to help customers improve the energy efficiency of their homes. Depending on your personal circumstances, this scheme could provide up to 100% of the costs for purchase and installation.

However, in order to be eligible for this scheme, you must be in receipt of certain benefits, such as Pension Credit, Working Tax Credit, Income Support or Jobseeker’s Allowance and have an annual income of less than £31,000.

Applicants apply for the scheme through their installer.

Want to explore more insulation grants? Check out our page on Government Grants for Insulation.

How long does loft insulation take?

Most loft insulation takes less than a day to install, especially when installed by a professional installation company. This might take longer if you opt for a DIY insulation project – but we wouldn’t advise going down that route.

When does loft insulation need replacing?

Loft insulation needs replacing when it is in poor condition or is in the form of a dangerous material, such as asbestos.

Next steps

Check to see if you already have loft insulation, what material is and what condition it is in. If it is asbestos, it will have to be removed, and that will add to the cost.

However, if it is not asbestos and is in good condition, it might be a good idea to just top it up (for example with loose fill insulation), which will save on the cost.

Check your roof space for draughts. If the loft is draughty, this will affect your choice of insulation type.

Think your home could benefit from an extra layer of warmth? Pop your details here and we will put you in touch with expert installers who will be able to provide their best prices for spray foam insulation.

FAQs

The average cost of loft insulation, per square metre, in the UK is £5 per m² for blanket insulation, £7.50 per m² for loose-fill insulation or around £55 per m² for blown-fibre insulation. These costs include installation.

Current government guidelines recommend a depth of between 250 mm and 270 mm.

To be eligible for a government grant towards loft insulation, you need to own your own home or rent, be in receipt of some kind of benefit and have an annual income of no more than £31,000.