Determining who is responsible for maintenance and repairs is difficult when different legal entities own different parts of the same building.
Unit owners are solely responsible for the repair and maintenance of all appliances, fixtures, ..., and other building components located inside of their units. The boundaries that determine what is "inside" of a unit are defined as follows:
Upper Boundary: Top of ceiling board
You own the sheetrock on your ceiling, but not the joists/trusses it's attached to.
Lower Boundary: Top of subfloor.
You own the finished floor in your unit (i.e. the carpet, tile, or hardwood floor) but not the plywood or concrete directly below it.
Vertical Boundary: Outside face of wallboard
You own the sheetrock on the perimeter walls of your unit, but not the studs it's attached to. For interior walls, you own both the sheetrock and the studs.
Unit vs. Common Elements vs. Limited Common Elements
Roadways, driveways, pavement, sidewalks, and parking areas
Yards, gardens, trees, lawns, fences, and grassy areas
Exterior of buildings (brick, siding, roofing)
Exterior finish of unit doors, storage doors, and garage doors
Fire walls
Patios and decks
Damage from one unit to another