Field & trade terms
Rough opening
Also called: RO
A rough opening is the gap the framer leaves in a wall for a window or door before the unit goes in. It's deliberately a little larger than the unit so there's room to set it, shim it plumb, level and square, and detail the flashing and air seal around it. Get the rough opening wrong — off dimension, out of square, or the sill not level — and every step after it fights the error, from the unit not fitting to flashing that can't lap correctly.
How it shows up on site
You see rough openings framed with king studs, jacks, a header and a sill, sized to the manufacturer's rough-opening dimension for that unit. Before the window or door arrives, the opening is where the sill pan and flashing prep happen, so it's a checkpoint on its own, not just a hole.
What an inspector looks at
The check is that the opening matches the unit's required dimensions, is plumb, level and square with a flat level sill, framed with the correct supports and header, and prepped for flashing before the unit sets. An out-of-square or oversize opening gets caught here, while it's still framing and not yet a leak.
Because RTI closes items on a photo, the rough opening is documented before the unit and the finish close it up — dimensions, square and the sill-pan or flashing prep shown in frame, the record the opening was right before the window went in.
Checklists that put rough opening to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- Plumb, level and squareThe three basic geometry checks — truly vertical, truly horizontal, and corners at true right angles — that everything downstream depends on.
- FlashingThin sheet material lapped into an assembly to direct water back out at joints, edges and openings before it can get behind the finish.
- Blocking and backingExtra framing set inside walls to give later fixtures, casework and equipment something solid to fasten into.
- Dry-inThe point at which a building is closed to weather — roof, wall barrier and openings sealed enough to keep water out and let interior work start.
- MEP (mechanical, electrical, plumbing)The mechanical, electrical and plumbing trades — the systems run through a building's structure that get inspected at rough-in and again at final.
- FirestoppingSealing openings where pipe, conduit or cable pass through a fire-rated wall or floor so the assembly's rating is restored.
Knowing the term is step one. Proving it is the job.
RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.