I can portray brick/block or brick/brick more as a basic construction
thing
to Building Control and not say a thing about heating it. They've
already
approved brick/block.

also, i don't know if i should have _any_ insulation in the cavity -
might
just be empty.

I don't know if you _are_ planning to heat it (you haven't said), but
if the Building Control Surveyor does his completion inspection and
there's a radiator in there, he may well require you to retro-fit some
insulation.
--
thanks again hugo.

i will definitely heat it at some point, but it will be after the completion
inspection.

i'd just like to know if i'll be losing much insulation by using brick/brick
instead of brick/block.

i'd really like the traditional look of bricks inside since i've gone to a
lot of trouble to get it looking as original as possible.

cheers
paul