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 per year |
|---|---|---|---|---|
| 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 per year |
|---|---|---|---|---|
| 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.