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How much could correctly installed loft insulation save you?



The Energy Saving Trust estimates that a quarter an uninsulated homes heat is lost through the roof. This equates to higher energy bills and colder less comfortable homes. Correctly installed loft insulation can reduce this heat loss, keeping the heat within the habitable areas of the home and therefore reducing expensive energy bills.

In this blog we will look at the potential cost savings that can be achieved with a correctly insulated loft. For the purposes of this blog we will be looking at lofts used for storage, not habitable rooms, and insulated with 270mm of mineral wool insulation*.

*The current recommended depth and the most cost effective domestic loft insulation solution.

The exact cost savings that homes can achieve depends on the individual characteristics of the property. The savings depend on a number of factors including:

- The quality and cost of the insulation installed

- The current level of insulation

- General energy efficiency of the house

- How much you currently pay for energy

- The age of your property and its type

Let’s start with the expected costs of correctly insulating a loft with mineral wool insulation.


The Energy Saving Trust suggests loft insulation costs around £339 for an average home, installed by a professional unsubsidized installer. These estimates are based on insulating a home from no loft insulation to 270mm of ineral wool loft insulation. This cost ranges from £285 for a mid-terrace home to £395 for a large detached home. As you can see the costs are not huge.

Now lets explore the potential savings...

The Energy Saving Trust calculations are based on gas-heated homes with no loft insulation compared to 270mm of mineral wool loft insulation.

  • For a detached house going from no insulation to 270mm the saving is around £215 per year. With an Installation cost of approximately £395 the payback time will be 1-2 years.

  • For a semi-detached house going from no insulation to 270mm the saving is around £130 per year. With an installation cost of approximately £300 the payback will be 2-3 years.

  • For a mid-terrace house going from no insulation to 270mm the saving is around £115 per year. With an installation cost of approximately £285 the payback will be 2-3 years

  • For a detached bungalow going from no insulation to 270mm the saving is around £185 per year. With an installation cost of approximately £375 the payback will be 2 years


The above chart also reveals the carbon dioxide savings that can be achieved from correctly insulating your loft. Up to 950Kg of carbon dioxide can be saved annually if you own a detached home.

The benefits of correctly insulating the loft are clear:

  1. a warm comfortable home

  2. annual cost savings from reduced energy bills

  3. reduced carbon dioxide being released into the environment

So what are you waiting for, get up in the loft and make sure it is correctly insulated.

If you are also considering using your loft for storage, please read our previous blogs:

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