Why insulate?
For a warmer home. If your home is not insulated, most of the the heat will be escaping through the loft and walls. Wrapping your home in insulation will help to keep it, and you, much warmer.
For better health. There is significant evidence that living in a cold home can make many health issues much worse. Insulating your home can improve existing health conditions and help you to minimise your risk of contracting illnesses.
For lower bills. With insulation your heating won't have to work so hard to keep you warm. This will mean lower bills, often by many hundreds of pounds.
Loft insulation
Over 16m homes in the UK have installed loft insulation. The most common method is to lay rolls of mineral fibre in between the joists in the attic floor.
The recommended thickness of loft insulation is now 300mm (12 inches), however to qualify for assistance under this scheme you need to have less than 150mm (6 inches).
Having this initial level of insulation is the most important part and the savings you get from topping it up beyond that are much lower (law of diminishing returns). For example, if you had no loft insulation and put in the full amount, you might save up to £350 per year, but topping it up from say 200mm to 300mm might only save £30 a year but cost £450-£1000 to install. (Figures above reflect planned October 2022 capped prices).
Cavity wall insulation
Homes in Dorset built after 1900 usually have external walls made of two 'skins' with a gap between them. These are ‘cavity walls’ and the space between can be filled with insulating material to stop the warmth escaping. Cavity wall insulation is normally installed by drilling a series of small holes into the mortar and injecting the insulation material into the gap. Over 13 million homes in the UK have had cavity wall insulation installed and insulating them could save you £150 or potentially much more.