Definition
Rough-in is the stage of construction when plumbing, electrical, and HVAC lines are run inside open walls and ceilings, before insulation and drywall go up.
Rough-In, Explained
Once framing is done, the trades run their systems through the open walls: supply and drain pipes, electrical wire and boxes, ductwork, and low-voltage cabling. None of the finished fixtures go in yet; this is the hidden infrastructure.
After rough-in, the city inspects the work while it’s still visible. Only after the rough inspections pass can insulation and drywall close the walls.
The word also describes a measurement: a toilet "rough-in" is the distance from the wall to the center of the drain, which decides which toilets will fit.
Why It Matters for Your Project
Rough-in locks in where everything goes: outlets, light fixtures, shower valves, vanity drains. Changing your mind after drywall means cutting walls open again, so layout decisions need to be final before this stage.
What to Watch For
- Walk the space at rough-in and confirm outlet, switch, and fixture locations.
- Have your fixtures and appliances chosen, since rough-in depends on their specs.
- Take photos of open walls before drywall: they’re a map for future work.
- Don’t close walls until rough inspections have passed.