We are remodeling master bath in FL house--concrete block exterior and bath has three sides on exterior corner--
shower and tub are coming out--and adding larger 4x6 shower on wall where tub is now...
contractor who will likely do the job (can't get anyone else to follow through) sent initial scope of work today--
doesn't mention adding any insulation to walls where shower and tub are coming out--
doesn't mention any weather stripping/insulation around window that is in current shower stall...we are taking out existing linen closet on that wall beside shower that is coming out--replacing with larger linen closet and some cabinets under the window--so new dry wall will be needed in some areas...
I think this window which was changed out for original several years ago by other owners might be part of reason there is water damage behind tiles in shower...

DO these concrete block homes have insulation--there is only a very shallow build out with flat firring stips behind the sheetrock now from what I understand--
if you can't do real insulation, should there be a vapor barrier?

nothing like that was mentioned in the scope of work...although he will use a vinyl membrane in the shower stall...