insulating garage

Hello. I'm about to convert my garage into a habitable space (not moved in yet, but have exchanged contracts). It’s a single skin thermalite block construction, and rendered on the outside, plastered on the inside. The main issues will be solving a small patch of damp (see photo) and sorting...

Hi all, I'm anticipating the answer is b"how long is a piece of string" but hoping I might get a steer in the right direction... I've got a detached garage built c.2000, 5.6m x 5.4m, pitched roof, 2.7ish floor to rafter, 14ft x 7ft up and over door, metal side door. Cavity walls, brick...