I had cavity wall insulation. If your house doesn't have cavity.

It depends how your house was built. My house was built with a layer of big grey hollow bricks, and a layer of red small bricks, 1982.

I think you'd best to ask your neighbors about this.

There is normally a grant for house insulation, covers about half of the costs. Ring up your local council, they will give a list of firms. Get one of the firms to come around giving a quoat, they will know what's going on.