Was it a modern house built to modern fire codes? If so, there's a good chance there was drywall behind the plywood on some walls. There's a reason even unfinis

Was it a modern house built to modern fire codes? If so, there's a good chance there was drywall behind the plywood on some walls. There's a reason even unfinished garages still get 5/8" drywall on walls shared with the house.