Rough-in is the construction phase when plumbing, electrical, and HVAC systems are installed inside walls, floors, and ceilings before drywall or other finishes cover them. During rough-in, pipes, wires, and ducts are run to their approximate final locations but not connected to fixtures or fully finished. Building inspectors conduct rough-in inspections to verify systems are properly installed before walls are closed, as defects would be expensive to fix after finishing. Rough-in follows framing and precedes insulation and drywall. The term distinguishes this infrastructure phase from 'finish' work when visible fixtures, outlets, and faucets are installed.