We had a builder construct an extension about 3 years ago, comprising
2 single bedrooms over an existing garage. The floors of the bedrooms sit on 5" joists with fibreglass insulation between the joists. The ceiling in the garage comprises of pink (fireproof?) plasterboard. The problem is that the front bedroom is very cold in winter and also soundproofing between the bedroom and garage is very poor. The back bedroom is not so bad because it is half over the kitchen. The garage isn't actually used as a garage, more a small workspace/ store. I suspect the builders have skimped fairly seriously on the fibreglass and I'm wondering what the best way to improve matters is. I'm thinking along the lines of (a) taking off the plasterboard and adding more fibreglass, (b) removing the fibreglass and putting 75mm Kingspan between the joists (c) leaving the ceiling as is and fixing sheets of 40 or 50mm Kingspan below it Not sure how (b) and (c) fit in with building regs even if the garage will never see a car!TIA for any advice Gelf