Loft insulation

Watch our video guide to loft insulation.

How loft insulation works

It acts as a blanket, trapping heat rising from the house below. You should also consider lagging your pipes at the same time for optimum efficiency.

The savings

If you currently have no loft insulation and you install the recommended 270mm depth you could save around £205 a year on your heating bills and around 1 tonne of carbon dioxide (CO ₂) per year.

The following table gives approximate costs, savings and paybacks for loft insulation.

The Government, energy suppliers and local authorities all provide grants or offers to help you implement energy saving measures in your home. For more information or to search for energy saving grants and offers, please click here.

	Loft insulation (0 - 270mm)	Loft insulation (50 - 270mm)
Annual saving per year (£)	Around £205	Around £60
Installed cost (£)	Around £250	Around £250
Installed payback	Around 1 year	Around 4 years
DIY cost	Around £300	Around £200
DIY payback	Around 2 years	Around 4 years
CO 2 saving per year	Around 1 tonne	Around 300kg

The installed cost includes the subsidy available from the major energy suppliers under the Carbon Emissions Reduction Target (CERT); the typical unsubsidised installed cost is around £500 for loft insulation to 270mm from either 0mm or 50mm.

How the savings add up

If everyone in the UK topped up their loft insulation to 270mm, over £700m would be saved each year. That's enough money to pay the annual fuel bills of around 550,000 families.

How it is installed

Insulation is simply laid over the floor of the loft, between and then over the joists if they are visible. Protective clothing, gloves and masks should be worn. Care must be taken not to insulate below the cold water tank, if one is present, and not to compress the insulation in tight corners or eaves. Walk boards can then be laid over the joists to provide safe access from the loft hatch to any water tanks (if present).

Loft insulation can be carried out as a DIY task or by a professional installer. There are grants and offers available to help you pay for loft insulation.

Find out if you're entitled to a grant or offer

What to do next

If you have other questions why not visit our FAQ section. If you still have other questions why not call your local Energy Saving Trust advice centre on 0800 512 012 for free, impartial advice on saving energy in your home.

• Find Energy Saving Recommended loft insulation

• Savings assumptions

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