How much will I save?
There are many different figures quoted for how much money insulation will save you. The answer is – it depends on a number of different factors, such as:
- How much insulation is already present
- The size of the building
- How many external walls there are (i.e. if the property is detached, semi-detached or a flat)
- The fuel used to heat (and/or cool) the property
The average savings that can be made by insulating a typical home can be found in the table below.
|Measure||Annual saving per year||DIY cost||DIY payback||CO2 saving
|Loft insulation (if no existing insulation is present – i.e. laying 270mm)||Around £180||£50 – £350||Less than 2 years||Around 730kg.|
|Loft insulation (if topping-up – i.e. laying 100-270mm)||Around £25||£50 – £350||From 2 years||Around 110kg.|
Cavity wall insulation and solid wall insulation are also great energy saving measures, however this entails the use of a professional installer.
|Measure||Annual saving per year||Cost||Payback||CO2 saving
|Cavity wall insulation||Up to £140||£450 to £500||Under 4 years||Around 560kg|
|Solid wall insulation (internal)||Around £460||£5,500 – £8,500||Varies||Around 1,800kg|
|Solid wall insulation (external)||Around £490||£9,400 to £13,000||Varies||Around 1,900kg|
Remember – these savings are made every single year, so making an investment in insulation now will save both energy and money, year in, year out.
1 The costs and paybacks shown are approximate, are provided for illustrative purposes only and are based on a gas heated semi-detached house with 3 bedrooms. The savings are the same as those used for CERT, assume a gas price of 4.39p/kWh and include a reduction factor for comfort taking. Installed costs and paybacks assume that installation is undertaken by a professional installer, unless otherwise stated, and both loft and cavity wall insulation costs include a subsidy which can be obtained under CERT. The total, unsubsidised cost of installing either loft or cavity wall insulation is typically around £500. Source Energy Saving Trust, February 2013.