Thanks for the reply mike.

If this is a garage, built as a free standing building without another
habitable building on top why are you putting in a cavity?

it is detached - about 100ft from the house at the bottom of the garden.

the reason i'm putting in a cavity is that i need reasonable insulation.
i'll be spending a lot of time in there and i also would like reasonable
temp / humidity control for comfort and the preservation of an old car.

additionally, in the fullness of time, i might want to put a small room in
the attic space (i'll create the roof using attic trusses) with velux,
settee, telly, etc for my wife to spend a bit of time while i'm pottering
about on projects at night. i'm good that way.

If you are building with a cavity then it is best to fill with insulation
batts.

what is this exactly? the architect has specified 50mm "cavity" - i'd
assumed it was empty.

Thermalite or similar will give a much better "U" value than commons

thanks - i had kinda assumed that the blocks would be better. however, i'd
love to keep things as original as possible and like the idea of common
bricks inside - it's a conservation area and i've already gone to a lot of
trouble to get a big garage to fit in unobtrusively.

my main concern is that i'll not lose a lot of heat with the right
brick/cavity/brick setup, compared to brick/cavity/block.

Obviously you have applied for planning and building regulations and
therefore your plans will give you an idea f what the local authority have
requested and passed

It seems they're not concerned at all about insulation, since it's a garage.

The foundations (700mm*450mm), etc are all defined to take quite a load
which i'm happy about.


all help appreciated

thanks again

paul