Since you re trying to control the bedroom and the insulation will fall to the ceiling of the garage look into air ceiling the crawl space so that air cannot penetrate from the outside.
Insulate garage roof below bedroom.
The picture below shows the garage and the dormer window of the 4th bedroom.
If your ceiling is unfinished you can do this from below before attaching drywall to the undersides of the joists.
One of the easiest ways to insulate the ceiling of your garage is to infill between the joists with batts of fiberglass or rock wool insulation.
Homeowners also should insulate a garage completely including in the attic above it if they plan on turning the garage into another air conditioned room.
So before insulating go around the garage with a can of low expanding spray foam and seal all gaps and cracks that let in the daylight.
Insulated garage doors typical only add about an r 3 5 insulation barely enough to make a noticeable difference.
Something to look into would be dense packing cellulose.
This can be done through blown in insulation and unfaced or faced batt insulation.
The ceiling is currently drywalled and i could see some r 9.
Hi everyone i have a split ranch with a 2 car garage under the bedrooms.
To insulate the floor of the room above the garage seal the space between the floor of the room and the ceiling of the garage and the top plate and the header joist with insulation.
There are no windows the joists are 9 tall and i am in massachusetts.
If someone spends a lot of time in the garage insulating it may improve their comfort even if it doesn t lower any bills.
The back wall of the garage is completely below grade the left wall is half below grade slope the right wall connects to the 1st floor and the front wall has two 8x7 insulated doors.
I know heat rises but i think the bedroom must be losing a fair bit of heat into the cold garage below.
You can insulate the walls ceiling and door of the garage to the highest r value possible but if you fail to fill those air gaps you ll still be wasting a lot of heat.
A better way to assure a warm and cool bonus room is to condition the garage space below by heating it or cooling it as needed.