No pictures here, sorry. I have an attached 3 1/2 car garage. Approximately 40% of the perimeter walls have the house interior on the otherside so they lose no heat and probably radiate some interior heat. The exterior garage walls are R14, the ceiling is 12 inches of blown celluose. I have three single car garage doors, chosen so I don't let all the cold in when a car goes in or out. Those doors have 2 inch foam insulation. These doors fit pretty good against the seals but there are a few small air gaps. We practice garage door "discipline" opening only when needed and closing as soon as possible. With that being said, my unheated garage will dip into the high 30's , 38 or 39 degrees F when we have 0 degree weather. Normally I see 42-45 degrees in my garage with out heat. I have added an oil filled electric heater set at 600 watts on occasion in the area I work and that made it pretty comfortable for me with a fleece outer layer.
I have a pretty good grasp of the garage temps because I have H/C running water on an interior corner so I monitor the temps to avoid frozen plumbing.
I have a pretty good grasp of the garage temps because I have H/C running water on an interior corner so I monitor the temps to avoid frozen plumbing.