I have listed some of the options / ideas of what I am going to do with each part: 1. Bathroom Ceiling: Option1: 5/8 greenboard 6mil plastic sheeting on attic side, greenfiber blow-in up to a recommended amount to achieve a high R-Value Option2: 5/8 greenboard Faced Fiberglass Insulation Batts (faced down toward the bathroom ceiling) On top of batts, greenfiber blown-in to a recommended amount to achieve a high R-Value Which option would make more sense? 2. Exterior Wall (will have no fixtures / no running pipes, just a window) Ultratouch batts 6mil plastic sheeting 5/8 greenboard (for better insulation) 3. Tub/Shower wall surround: No insulation in wall cavities 6mil plastic sheeting ½ Durock Shlutzer Kerdi membrane Tiles 4. Also, I will be insulating a garage ceiling, so our bedroom (which is directly above this unheated garage) will be much warmer in the winter months. About 2 of insulated sheathing (like XPS, EPS, or Polyiso, etc.) Ultratouch batts 5/8 Type X Drywall In terms of insulated foam sheathing, I am not sure which one would be best for this project. Should I use boards that contain laminated facers on both sides, on one side, or neither, just unfaced? Should I use XPS, EPS, or Polyiso? Please, advice / comment on all of these above points. Thank you.