In a country with cold winters is it possible to build a floor over a garage?

Question

The garage is unheated and this floor would hold 2 bedrooms and a bathroom. Builder says it is feasible, I say there is no way to make it a comfortable place.

Answer 1

2lb spray foam insulation will make the floor warm and toasty. Keep the bath closest to the warm side of the building so that the drains don't freeze. Do not put any other water lines in this area in any cold areas. Yes it can be done easily enough

Answer 2

Not only insulation, but you might consider heated floors. In a cold climate, it would be well worth it, and would assist in keeping water pipes from freezing. Is there any reason the garage could not become a heated one? an above-garage apartment would be very comfortable then.

Answer 3

New room additions over unheated garages happen all the time in cold climates. Insulate the floor joist cavities with fiberglass batt insulation and a vapor barrier. Extend the air ducts into the area and you should be good to go.    

Answer 4

Sure, you just use lots of insulation and make sure there's adequate supply and return duct work.

Answer 5

Well, you are going to have to heat the space, so I wouldn't be too worried about that part of it.

To keep your heating bill lower, you need to insulate the walls and ceiling.  Insulate the ceiling of the garage too.  For code compliance, you will have to put 5/8" Drywall - Firerock - on the ceiling between the garage and any living space anyway.  In the US, anyway.

Heat rises.  If you insulate the walls and ceiling, the room will be warm.

Answer 6

if you insulate  the garage ceiling very well and install 220 volt electrical floor heating under ceramic tiling it should do the trick