How much does loft insulation cost in 2023?

Is insulating your attic energy efficient?

An uninsulated home can lose a quarter of its heat, just from the roof. With a 40-year lifetime, correctly installed loft insulation will pay you back several times over by reducing your energy bills every year. 

This is how much you could save on a yearly basis, by properly insulating your loft: 

Properly insulating your loft will also save thousands of kg in CO2 emissions, helping you reduce your carbon footprint. 

Want to reduce your energy bill even more? Check out our cavity wall insulation cost guide.

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Which loft insulation is best? 

The type of insulation you get will depend on how easy it is to access your loft, and whether you want to install your insulation yourself or hire a professional. Different insulations use different materials, so it’s also worth considering how eco-friendly you want to be. 

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How long does it take to install loft insulation? 

Most loft insulation installations take under a day and can be completed within a couple of hours. Blanket installations take less time than sheet installations, but you can expect labour costs to be about the same, especially if you’re paying a daily labour rate. 

It will take longer than this to install insulation if you’re doing it yourself. 

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How much does it cost to insulate a loft? 

Looking at average installation costs for an entire loft, you could pay around: 

The bigger your loft, the more it will cost to insulate, especially if you end up having to pay for additional services, such as rewiring electrics. The type of insulation you get will also affect costs. The above examples include the cost of blanket loft roll insulation.

To find out the prices for different insulation types, let us know what you have in mind by speaking to a skilled tradesperson today.

Can I insulate my loft myself?

If you do want to install insulation yourself, then the above costs will give you a sense of how much materials will set you back. Though some types of insulation can be installed DIY, professionally installed insulation lasts longer, and is generally more effective.  

Since insulation is installed primarily to be as cost-saving as possible, we recommend you hire a professional, unless you are confident you can insulate your loft properly yourself. 

If you do want to do it yourself, you should keep a few things in mind: 

1. Make sure the wiring in your loft is kept above the insulation. If your wires are getting stretched because of your new insulation, then you should hire an electrician to reroute them. 

2. You should clean your loft and clear it of any stuff that is being stored there before you begin insulating, regardless of whether you want to DIY or hire a loft insulation installer. 

3. Don’t forget about your pipes and tanks. These will need to be insulated as well to prevent them from freezing. 

4. If you want to use your loft as a storage space, then you’ll need to lay boards over your joists. If you want to convert your loft into a room, you’ll need to hire professionals to do this. 

5. Don’t use less than the recommended amount of insulation. The government recommends insulation of 270mm thickness. Using a thinner size will cost you money in the long run, because your less efficient insulation will raise your energy bills. 

6. Make sure you don’t cover any vents whilst you lay down your insulation. Your loft needs to be properly ventilated to avoid damp from developing. If there aren’t enough vents in your loft, you may need to have additional ones installed. If you do have a lot of damp problems, then we recommend you don’t opt to DIY, as you’ll need a professional to help fix this before your insulation is installed. 

7. To calculate how much insulation you’re going to need, you need to know the floor area of your loft (length x width), and the depth of insulation you already have.  Knowing the joist heights in your loft is also a good idea, so that you can know whether to lay the first layer of insulation between joists. Don’t worry about your old insulation, you can lay new insulation over it (just make sure you’re not squashing it down).  

Using 100 mm thick insulation rolls with a 8.3 m2 coverage, you can calculate how many rolls you’ll need by doing: Area (in sq m) x (1 – 0.1) ÷ 8.3 sq m. This is the equation you need for laying a base layer (25mm or less of existing insulation). If you want to add a top layer over an existing layer of insulation (for instance 100mm), the equation would be: Area (in sq m) ÷ 6.47 sq m (using 170mm rolls with a 6.47 m2 coverage). 

DIY loft insulation installation will save you from having to hire an installer but might mean your loft will be less energy-efficient than it could be. 

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Loft insulation labour costs

If, on the other hand, you want to hire someone to insulate your loft for you, so that you can ensure everything is done correctly and you maximise the heat retention in your home, then you can do so here.

The average loft insulation costs around £450 and £1,200 (labour costs only) for the entire project. How much you end up spending depends on the scope of your project, and where you live in the UK.  

Labour costs rise in London and the South East, sometimes by as much as 20% more on average. 

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Additional costs

• It costs about £5 – £8 per metre to insulate pipework (materials and installation) 
• It costs about £150 to insulate a water cistern held in your loft 
• You may also need to relocate electrical wires during the insulation. An electrician will charge around £250 a day to do this 
• A loft ladder and hatch will cost around £350 (materials and installation) for an existing opening. You’ll have to factor in another £250 if you’re looking to build a new opening to your loft 
• If you need new loft legs (stilts), it will cost around £600 for an average loft, using chipboard. This will take roughly a day to do