Loft insulation can help you make your home more energy-efficient and reduce your heating bill.
An extra layer or two of loft insulation can result in savings of up to £250 annually. This means it can easily be paid back within 2 years.
This article will cover what you can expect to pay for loft insulation and the factors that affect the price of loft insulation. This ensures you have a ball-park figure of what to pay before contacting a loft insulation specialist.
Average Loft Insulation Cost Per Metre
Below is a breakdown of the costs that make up a loft insulation installation.
| Item | Labour Cost Per m² | Material Cost Per m² | Total Cost Per m² |
|---|---|---|---|
| 100mm rockwool | £5 | £6 | £11 |
| 150mm rockwool | £5 | £9 | £14 |
| 200mm rockwool | £5 | £12 | £17 |
| 100mm earthwool | £5 | £3 | £8 |
| 150mm earthwool | £5 | £3 | £8 |
| 200mm earthwool | £5 | £4 | £9 |
| 100mm celotex board insulation | £11 | £15 | £26 |
| 150mm celotex board insulation | £11 | £24 | £25 |
| 200mm celotex board insulation | £11 | £32 | £43 |
The prices are for London and South East England. See the factors section below to adjust to your area.
It’s fairly common for loft insulation to be done in two layers with different thicknesses of insulation product used.
The first layer would be placed directly between the joists in the roof space with the second layer being laid flat across the top of the joists and insulation.
Factors that Affect the Cost
Grants Available
There are currently grants available for low-income householders as well as the government Green Home Grant voucher comes into effect at the end of September 2020, which provides up to £5,000 or £10,000 to households to install low carbon heating and insulation improvements.
Existing Loft Insulation Thickness
The minimum recommended thickness of insulation of 270mm. Depending on the thickness of your current insulation, you may need to have either one or two extra insulation layers to exceed the 270mm standard.
Generally, if you require a second layer you can expect to save £2/m² compared to the first. I.e if you pay £8/m² fo the first layer, you should get the second layer for £6/m².
Size of Loft
A larger loft size will require more insulation, thereby reducing the cost per m².
Access Issues
Lofts with difficult access often have small hatches or very little space. This means standard loft insulation rolls aren’t as suitable and a loose, insulation material needs to be blown into the loft with specialist equipment. This will increase the cost.
By removing all the clutter within the loft, it should be far easier to work in and ensure all the available area is covered.
Location
Labour costs in London and the south of England are generally more expensive than elsewhere in the UK.
The prices quoted in the table above apply for the South East or Outer London area. The adjustments below can be used to calculate costs in your area.
Region % Adjustment
South East (Southampton, Oxford, Kent, Outer London) 0
Inner London +4%
South West (Bristol, Exeter) -4%
West Midlands (Birmingham) -10%
East Midlands (Northampton, Nottingham, Leicester) -10%
East Anglia (Cambridge, Norwich, Ipswich) -5%
North West (Liverpool, Manchester) -12%
Yorkshire and Humberside (Leeds, Sheffield) -11%
North East (Newcastle, Sunderland) -10%
Scotland (Edinburgh, Glasgow) -6%
Wales (Cardiff, Swansea) -9%
Northern Ireland (Belfast) -12%
What Depth of Loft is Needed?
Currently regulations advise a depth of at least 270mm for loft insulation for a blanket type insulation using materials such as mineral wool.
Loft insulation that was previously installed a few years ago would have been up to a depth of 200mm and older installations would have used insulation a maximum of 100mm deep.
How Does Loft Insulation Work?
Loft insulation works by ensuring that any heat rising through a building is contained within the fibres laid down.
Loft insulating materials are poor conductors of heat thereby reducing heat loss by conduction. Prevention of air circulation reduces heat loss by convection.
Approximately 25% of heat within a house is lost through the roof.
How Do I Get Free Loft Insulation?
Grants are available for insulation laid in a loft. The loft must be easily accessible and have either no insulation or less than 100mm to qualify for a grant. This will ensure that the depth is brought up to a level of 270mm
The ECO scheme (known as the Energy Company Obligation) necessitates energy-efficient technologies to be installed by the main energy suppliers to domestic homes. These can include technologies like loft and cavity wall insulation.
How So You Install Basic Loft Insulation?
Two of the most common ways of applying loft insulation are as follows:
- On the base of the loft, lay roll-out pieces of insulation. The insulation is usually fibreglass or wool and is laid between the joists.
- This method is less popular than the rolled fibre but involves blowing loose-fill insulation using a hose. This pressures the air to form a foam-like insulation. This method is used more where access is restricted.
How Long Does Loft Insulation Last?
Loft insulation if looked after should last for 40 years and will cover the initial cost many times over.
Get Prices On Loft Insulation Near You
We’ve done our best to give you a good idea of what you can expect to pay for loft insulation.
However, our guides are not a substitute for a fixed quote specifically for you from a specialist.
We work with all the loft insulation installers ready to price your job. Get free, no-obligation quotes in your local area and compare prices using the form below.
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About the Author
Alex Johnson is a qualified quantity surveyor and writer with a passion for conducting original research and uncovering the true cost of jobs. His cost data has been referenced by EDF Energy and the Scottish Government.