Loft insulation

Uninsulated homes lose a quarter of their heat through the roof. With loft insulation, you can keep your home warm and reduce your energy bills.

Loft insulation is a layer of material between your home’s ceiling and the roof. The insulation material slows down heat as it tries to escape from the top of your home.

FAQs -Loft insulation

If you’ve been offered the opportunity to have loft insulation installed at your home, these FAQs should answer any questions you may have.

Loft insulation is material installed between the roof and ceiling of a building to prevent heat escaping through the roof. The insulation material slows down heat as it tries to escape from the top of your home and improves the energy efficiency of the property.

25% of heat is lost through the roof of a home with no loft insulation. Insulating your loft or roof is an effective way of reducing heat loss and reducing your energy bills. If loft insulation is installed correctly, it has a lifetime of 40 years, which should more than pay for itself in this time.

If your loft is easy to access and the loft joists are regular, rolls of mineral wool can be used to insulate the loft. The first layer is laid between the joists, which are the horizontal beams that make up the floor of the loft. A second layer is laid at right angles to cover the joists, which makes the insulation up to the required depth.

If you want to use the loft for storage, boards will need to be laid over the joists and the insulation will need to be thick enough. You may need to raise the level of the floor so that enough mineral wool can be fitted beneath the new floor level. To raise the level of the floor, timber battens are fitted across the joists or plastic legs are fixed to the joists, to support the new floor.

Loft insulation will keep your house warmer but make the roof space cooler.

The following figures from Energy Saving Trust* are the annual savings based on estimates of insulating a gas heated home with an uninsulated loft, to the recommended depth of 270mm of mineral wool insulation.

Detached house – £380
Semi-detached house – £230
Mid-terrace house – £200
Detached bungalow – £370

*figures correct as of February 2025

Installing lost insulation in your home should cause minimal disruption as most of the work will be carried out within the loft space. The contractor will need access to your loft space and may need to carry materials through your home but other than that the disruption should be minimal. The contractor will talk you through the install process.

Yes, there should not be any reason for you to need to leave the property while the loft insulation is being installed.

Useful pages

Saving energy in the home

Saving energy in the home is good for our pocket and the planet. There are lots of little changes we can make – many costing us nothing at all – that can add up to big savings.

Energy bills and your supplier

From getting to know all the charges that appear on your energy bill to the best ways to find out about your rights, our advice and support can help you take control.

Financial support

Financial support is out there, whether you’re struggling with your energy bills or looking into funding for renewable heating systems. Our guides cover what financial support is available, and how to apply.

Managing your heating

The more familiar you are with your heating systems, the better. Use our guides to take control of the heat in your home and use it more efficiently.

Templates for writing to your energy supplier

We’ve put together several templates to help you write to your energy supplier. The templates cover common energy supply issues and can be used for emails, webchats, or letters.

Get a retrofit

If you’re thinking of retrofitting your home to make it more energy efficient, Changeworks has a number of funded and self-funded options available.