How much will I save?

How much will I save?

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:


  1. How much insulation is already present
  2. The size of the building
  3. How many external walls there are (i.e. if the property is detached, semi-detached or a flat)
  4. 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 £150 £250-350 2-3 years Around 800kg.
Loft insulation (if topping-up – i.e. laying 50-270mm) Around £45 £200-300 Around 5-7 years Around 230kg.


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		 DIY cost DIY payback CO2 saving
per year
Cavity wall insulation Around £115 Around £250 Around 2 years Around 610kg.
Solid wall insulation (internal or external) Around £400 Varies Varies Around 2,000kg


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.

Installing insulation also contributes to the energy performance of a home, which is assessed as part of the Home Information Pack (HIP) required by law before a home is put on the market. Ensuring a home is well insulated will boost its energy efficiency rating and could make it more attractive to potential buyers or tenants.

Click here to find out more about home energy efficiency ratings and HIPs.

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. Professional installation costs and paybacks assume that installation is undertaken by a professional installer and are un-subsidised. Note that grants and offers are available from local authorities and energy suppliers which can reduce the cost and payback times substantially. Savings assume a gas price of 3.80p/kWh. Some of the savings made may be taken in increased comfort. Source: Energy Saving Trust, 16th July 2009