qwerty is correct, singleskin blockwork that absorbs rain then freezes in the winter, brrrrr!
my garage is now covered in ivy, not a quick solution for sure, but very eco friendly,
i`m amazed how dry it is, and seems if its dryer its less prone to condensation, even though it may be frosty,
and, i had wrens, robins, 2 x blackbirds and doves nesting in it this year 🙂