workshop; craft room
A room or space equipped for hands-on work such as woodworking, crafts, or model-making. Often found in schools, community centers, or as a personal hobby space.
I made a bookshelf in the school workshop.
On weekends, he shuts himself in his workshop and builds models.
作業場 is a broader term for any work area, including industrial or outdoor sites, whereas 工作室 specifically suggests a room for hands-on crafting.
Compound of 工作 (こうさく, 'crafting, construction') and 室 (しつ, 'room').