The insulation costs in this article are correct as of 2019
There are many ways to insulate your home, and many good reasons to do it. Heat escaping your home makes your property colder, makes it less energy efficient and less environmentally friendly, and costs you more in heating bills. But insulation, whether in the roof, loft, or walls of your home, can help keep in the warmth and save you money in the long run. This guide is designed as an overview of home insulation costs, while more detail about each area can be found in the specific price guide.
Loft insulation at its simplest involves putting down an insulating material such as fibreglass or mineral wool over the joists of your loft, or filling the spaces between the joists with foam or beads, to help retain heat in the rooms below. It is probably the cheapest way to add insulation to your home, and can be done in most properties for between £300 and £400, barring any complications that might arise.
Insulating a roof directly, so that the attic or loft is a useable space which retains heat, is more expensive than lagging the loft, but can still be cost-effective in the long run. It entails using insulating boards under the pitched slope of the roof itself, or else using spray foam to coat the underside of the roof and the rafters. Generally, good insulation can be achieved for between £400 and £500 in a typical property.
If you wish to insulate a flat roof, this can cost more, depending on the technique you choose to use, but can range in price from equivalent to pitched roof insulation to more than twice as much.
Another popular way to insulate your home and an easy win if it hasn’t already been done is to install cavity wall insulation, filling up the space between the internal and external layer of brick that makes up your home’s exterior walls. This involves drilling holes in the wall then pumping in an insulating material. It can be achieved for around £200 for each two-storey exterior wall you want to be treated.
More complex, and more expensive, is interior wall or exterior wall insulation, which can be added to solid walls, those built in a single layer without a cavity to fill. These procedures can range from around £4,000 to more than £20,000 depending on which method you use and the size of your property.