Three different jobs hide inside "move that window"
A cut-in is a brand-new opening in a wall that never had one. A relocation is two jobs: an opening closed and rebuilt as wall, and a new one framed somewhere else. An enlargement widens, drops or raises an existing opening. They share a method but not a scope, and the sequence of trades differs for each. Getting the name right on the estimate is the first place a project stops drifting.
Before the saw: what that wall is doing
Nothing gets marked until four questions are answered, from inside as well as out.
- Is it carrying load? Which way the joists or trusses above run tells you most of it. A wall parallel to the framing above may be carrying only itself; a wall perpendicular to it is usually carrying a bearing line.
- What runs through the bay? Wiring, supply and waste plumbing, a vent stack, a gas line, a duct. A waste stack in the middle of the proposed opening is not a reason to cancel, but it is a plumber and a week.
- Is the sheathing doing bracing work? See the next section. This is the one that gets skipped.
- What are the barrier and the cladding? How the patch ties back into the existing drainage plane is decided before the first cut, not after.
Header sizing is a span calculation, not a habit
The header carries whatever sits above the opening and hands it down through the jack studs at each end to the plate, the rim and eventually the foundation. Its size comes out of the span tables published with the residential code (clear span, what the wall is carrying, species and grade), and the same tables set the number of jacks under each end. Widen an opening and the span grows while the load path narrows to fewer points.
Two conditions send it to an engineer rather than a table: a span the tables do not cover, and a point load landing near the opening (a girder truss bearing, a post from above, a beam pocket). If a job needs a stamp we would rather find that out at the measure visit than with the wall open.
Shear: the part nobody quotes
Walls do two structural jobs. They carry gravity, and they resist the racking that wind and seismic loads apply sideways. The second is done by braced-wall panels: full-height sections of sheathed wall of at least a minimum length, counted along a braced-wall line. A new opening in the middle of a long blank wall may cost that line nothing. The same opening near a corner, or in a wall already short on bracing, can drop the line below what it needs.
When it does, the fix is not more nails. It is a designed solution: a narrower engineered panel, a portal frame with its own hold-downs and strap, or bracing redistributed elsewhere on the line. Garage-front walls, walls with a run of windows already in them, and the short returns beside a corner are the three places we expect the answer to be "get it looked at".
What the opening has to satisfy once it exists
Two code items reliably change an enlargement. The first is emergency escape and rescue: a bedroom window has to give a minimum net clear opening, with minimum clear height and width and a maximum sill height above the floor. Net clear is measured through the operating sash, not across the rough opening, so a unit that drops straight into the hole can still miss it. The second is hazardous-location glazing: openings near doors, near walking surfaces, low to the floor, or in a bath or shower area need safety glazing, and what you have is etched in the corner of the pane. Both get read off the schedule before the unit is ordered, because reordering in tempered is weeks of hole in the wall.
Dry-in sequence at the new opening
This is the twenty minutes that decides whether the wall is dry in a decade, and it only works in one order.
- The barrier is cut at the opening, side and bottom flaps folded in, head flap cut on the diagonal and held up out of the way.
- A sill pan goes in with a back dam and turned-up ends, lapping out over the face of the barrier below so anything reaching it drains outward.
- The unit is set plumb, level and square (diagonals measured, not eyeballed) and shimmed at the bearing points the manufacturer nominates.
- Jamb flashing over the flange and over the barrier face.
- Head flashing over the jamb flashing; then the barrier head flap drops over the head flashing and the diagonal cuts are taped.
- Sealant where the instructions say and nowhere else. The bottom of the unit stays open so the assembly can drain. Sealing that joint is the most common well-intentioned mistake we open up.
Patching the cladding back in
The framing decides whether it works. The patch decides whether you like it.
- Vinyl. Courses unlock with a zip tool, so the mechanics are easy. The limit is colour: a profile from ten years ago may be out of production, and a live colour still arrives brighter than the weathered wall. Pulling material from a hidden elevation and patching there instead usually looks better.
- Fiber cement and engineered wood lap. Cut back to framing so the new butt joints land where they can be flashed, stagger them away from the old ones, blind-nail to the schedule, seal cut edges per the manufacturer. Factory finish rarely matches a field-painted repair, so plan the paint break at a corner.
- Stucco. The hardest to hide: lath has to tie into existing lath, the weather-resistive layers have to lap correctly, and the texture is hand work that telegraphs under raking afternoon light. Refinishing the elevation is often the only result people are happy with.
- Panel siding. Break the patch at a full sheet edge over framing. A partial-sheet repair announces itself along the seam within a season.
Permits, inspections and who says yes
Structural alteration is a different animal from swapping a unit into an existing hole, and requirements are set by the building department with jurisdiction over the address. They are not the same everywhere in the region, and not ours to guess. We confirm the scope with that department before anything is scheduled, so inspection points land in the programme instead of stopping it. Framing and dry-in are typically things somebody wants to see before they are covered, which is a reason not to book the drywaller for the same afternoon.
What a written scope should name
- The framing package (header, jacks, kings, sill and cripples) and who sized it
- Whether an engineer is involved, and who pays for the stamp
- The flashing detail and barrier tie-in at every new opening
- The patch method, and whether the elevation is patched or reclad
- Whether interior finishing (drywall, texture, paint, trim) is in scope or excluded
- The window: line, style, glass package, tempered where required, and the freight window the manufacturer has given us
If you are planning an opening of your own, our page on window styles, frames and glass packages walks through what can go in it.