yeah thought so ,,,,,,,my neighbour did his garage and i checked a few things out as it progressed,,,,,,but couldnt stand over the joiners every second of the day ,,,,ha ha ,,,,,,,would have got a hammer rammed up somewhere eh,,,,, different folk have told me do bricks 1st then window others the opposite ,,,,,,i think window 1st then i can do my frame to fit eh otherwise bricks would get in the way ????????? also the inside window sill height could be determined?,,,,,,,,the order from inside to out i have taken note ,,,, gyprock with the silver backing is that a vapour barrier? ,,,,i will be using kingspan,, does that have a breathable membrane,,,,, why im asking these questions is guy across the road used osb then kingspan then gyprock if he screwed up by making shortcuts good luck to him but i dont want to ,,,,,,, he made many short cuts and they have already started to haunt him ,,,,,,,he is younger ,,,,,ha ha ,,,,,i remember those days of ducking and diving but you always get caught out in the end ,,,,,,,im ancient now ,,,,,,learnt my lesson ,,,,,,,hope you are not young and take offense ,,,,,,,,,,cheers