We are having it installed in our 1930's red brick semi soon. It has a
single story extension on the side, and during the survey I was told that
the portion of old exterior wall now enclosed by the extension will still
need drilling and filling. I don't see why as it's no longer outside and so
can't loose heat other than into the extension which is itself heated. If I
can get them to leave this wall then it would save a lot of cleaning up and
redecorating afterwards.

Any thoughts ? the filling will be blown fibre which is both sticky so it
stays in place and also treated against moisture.

--
Pete Cross