Another one of my "started not finished" items from eBuild now revisited! Seems easier to address now I've actually got a floor to stand on and ceiling above my head!   So.....this is the bathroom window. A generic DG window (Britelite maybe, the house has a mix) set flush with the outside of the outer leaf of the cavity wall. The wall is a mix of  block, breeze and brick. Heavy, uneven, painted render externally.     As I'm battening, insulating and VCL'ing the wa