A temporary wall was built to support the weight of the roof before we cut the hole for the new door and window.
Inside looking out
Both the window and door.
It's pretty cold here in Canada. We have winter for eight or more months a year. So to turn a garage into a studio we felt that it really needed to be insulated properly. After building the floor up to get it off the concrete we then spray foamed it. We also did this to the ceiling. It was expensive, but we just felt that that's where the majority of heat loss occurs. We used bat insulation on the walls.
Apparently this stuff is deadly in liquid form (hence the hazmat suits) but within ten seconds I'm told you can it eat. I didn't believe them so I made my kids eat a bunch. Turns out they were right...