Mary Fisher wrote:

In January 1993 we paid something over £300 for cavity wall insulation,
accompanied by the mocking of neighbours (just as they did in January 2005
when installed solar water heating). They said it wouldn't make any
difference to anyone except the company which did it.

SWI was quite rare in those days and we weren't eligible for a grant. We
felt the difference in comfort immediately, we didn't measure any money
saving but that wasn't the purpose.

I don't have much in the way of cavities to fill since my house is mostly of solid 9 inch brick wall
construction.

I did however notice the diference after it was painted with 'masonry paint'. It had previously suffered
from penetrating damp which results in higher heat losses. It 'feels' nicer too.

Graham