Granny23
I looked into this years ago. I do not have cavity walls - Cottage built of blonde sandstone 135 years ago. All they could offer was internal insulation boarding, which would have required redecorating throughout at my own expense. I did not have savings to cover this and the savings in heating costs would have been minimal.
We have similar. Stone built, 300yrs old. We have double glazed windows everywhere and the recommended amount of loft insulation. The stone walls seem to retain heat well once warmed. They only lose it if we're away from home for a few days. No need for wall insulation.
(It's lovely and cool in summer, too
)
@ Calistemon Weren't a lot of cavity walls found to be carelessly constructed with builders' waste dropped on the metal ties and causing a 'bridge' to allow damp across?