The savings for loft top up assumes moving from 50mm to a level of 270mm of insulation. Full loft insulation assumes moving from 0mm to a level of 270mm.

The savings for double glazing assumes replacing all single glazing in a house with C-rated Energy Saving Recommended double glazing.

The saving for installing a hot water tank jacket is based on a weighted average of a range of original insulation thicknesses.

Savings for buying Energy Saving Recommended appliances are based on replacing an old appliance with an A+ or A++ cold appliance or AAA wet appliance. Please note the savings for Energy Saving Recommended products are not related to the property or heating fuel.

Boiler savings assume average levels of insulation when replacing a stock average boiler with efficiency of 72% (gas) or 80% for oil with an Energy Saving Recommended condensing boiler with an efficiency of 90%. This saving assumes heating controls are already in place or will be installed with the boiler. If no heating controls were present before the new boiler was installed then the saving will be higher.

Heating controls assume originally having only a room thermostat, then adding a hot water tank thermostat and thermostatic radiator valves. This saving is based on having a stock average boiler with efficiency of 72% (gas) or 80% (oil). If controls are installed with a new boiler, the saving gained from going from no controls to the controls listed above will be lower because the system will already have an improved efficiency from the new boiler.

Saving assumes replacing all remaining standard bulbs with equivalent energy saving light bulbs in an average UK home. Please note the saving for lighting is not related to the property or heating fuel.

'Simple tips' (excluding turn thermostat down) are not related to the property or heating fuel type and take into consideration the heat replacement effect. They are based on an electricity price of 10p/kWh.

Click here to find out more about the heat replacement effect

The washing at 30 degrees savings assume all washes are performed at 30 rather than higher temperatures, and assume a 40% saving over a year.

Efficient Driving - visit the efficient driving pages of the web site to find out more about eco driving.

Savings for renewable energy technologies are not shown on the checklist as they are heavily dependant on many different variables which have not been taken into consideration in this checklist.

The total money and CO₂ saving do not include savings from renewables because the assumptions used to calculate energy efficiency measures are very different to those used for renewables. And the amount you can save with renewable energy technologies depends heavily on individual circumstances making it very difficult to provide any averages.

The total you can save in money and CO₂ is related to your home and therefore does not include the savings you could achieve with efficient driving.

General: These savings provide an estimate only, and generally are based on the averagely insulated home. Actual savings may be higher or lower depending on your original usage of energy and insulation levels.