Parts for this step · tap one to find it
The framed and sheathed room from the wall-framing guide gets three windows and an exterior door. The roof is on by now (hidden here so you can see in). The goal is simple: every unit level, plumb and square, and every opening lapped so water runs down and out, never in.
≈2–3 days for a crew, once the roof is on
This guide shows the sequence, not a design. Always follow the window and door maker’s installation instructions; many follow ASTM E2112, and your warranty can depend on it.
A water-resistive barrier goes over the sheathing, starting at the bottom so each course laps over the one below, like shingles. At each opening it is cut so the sides fold into the opening, and a flap above the opening is cut and taped up out of the way for now.
≈half a day · Shingle laps: upper over lower · stucco walls usually get two layers of building paper
Parts: ≈600 sq ft × Water-resistive barrier (house wrap or building paper)
Under stucco, the code calls for a stronger barrier, often two layers of Grade D paper. Siding usually goes over house wrap. The plans and the finish decide which.
Before any window goes in, each rough opening is checked: the sill level, the sides plumb, and the diagonals equal. Then the sill gets a pan of flashing tape that runs across the sill, up each side, and out over the wrap, so any water that gets past the window drains back outside.
≈2 hours · Sill level · sides plumb · diagonals within about ⅛ in · tape lapped out over the wrap
Parts: 3 × Sill pan: flashing tape across the sill, up the sides
Some crews tilt the sill slightly toward the outside first, or use a molded sill pan. The window maker’s instructions say what their window needs.
A bead of sealant goes on the wrap where the side and top fins will land, but not across the bottom, so the sill can drain. The window is set in from outside, shimmed under the sill until it is level, checked plumb and square, and opened and closed to be sure it runs smoothly. Only then is the fin nailed off.
≈1 hour per window · Level and plumb within the maker’s tolerance · diagonals equal · fin nails per the maker
Parts: jambs and head × Sealant bead (low-VOC, compatible with the tape); under the sill × Shims for leveling; 3 × Window: dual-pane, low-E, with a nailing fin
A window that goes in out of square will bind, leak and wear out early. A few minutes with the shims and level is the cheapest part of the job.
Flashing tape goes on in shingle order: first down each side over the fin, running past the top and bottom, then across the top over the head fin and the side tapes. The bottom fin is left untaped so the pan can drain, unless the maker says otherwise.
≈30 minutes per window · Order: sill pan → sides → top · every lap sheds water down and out
Parts: 2 per window × Flashing tape at the sides; 1 per window × Flashing tape across the top
The tape is pressed down hard with a roller. Tape that isn’t rolled can peel back and let water in.
The door gets a sill pan with a back dam, so water under the threshold has nowhere to go but out. Sealant goes on the pan where the door maker shows, and the prehung door is set in. It is shimmed at the hinges and the latch until the hinge side is plumb, the head is level and the gap around the door is even. Long screws through the hinges into the framing, as the maker shows, hold it, and the latch side is screwed through the shims.
≈2–3 hours · Hinge side plumb · head level · even ⅛ in gap around the door · threshold fully supported
Parts: 1 × Door sill pan with a back dam; per the maker × Sealant bead (low-VOC, compatible with the tape); 1 × Prehung exterior door with threshold; at hinges and latch × Shims for leveling
The threshold must be fully supported on the pan, with sealant under it. A threshold that rocks will crack the seal. Outside, a landing no more than about 7¾ in below the threshold is required at the door.
Most prehung doors have wood trim instead of a nailing fin, so the sides of the opening are lined with flashing tape and the trim is set in sealant. Across the top, a metal drip cap goes over the head trim, its flange is taped to the wall, and the head flap folds down over it later. Everything laps so water runs down and away from the door.
≈30 minutes · Same shingle order as the windows: sides, then the top
Parts: 2 × Flashing tape at the sides; 1 × Metal drip cap over the door’s head trim; 1 × Flashing tape across the top
Outside, the head flaps fold down over the top tape, and their cut corners are taped. Inside, the gap around each window and the door is sealed with low-expansion foam made for windows and doors, which won’t bow the frames. The door’s weatherstripping and sweep are adjusted so they seal all the way around without dragging.
≈half a day · Air sealing counts for the energy code too · inside, the seal goes all the way around · outside, the bottom fin stays open so the pan can drain
Parts: folded down × Head flap cut in the wrap above an opening; 1–2 cans × Low-expansion window and door foam; on the door × Weatherstripping and door sweep
Regular expanding foam can push a window or door frame out of shape. The can should say it is for windows and doors. Some window makers call for backer rod and sealant instead of foam.
Every window carries an NFRC label with its U-factor (how well it keeps heat in) and its SHGC (how much sun heat it lets through). California’s Title 24 energy code sets the limits by climate zone. Under the 2025 code, in the Los Angeles area and most of coastal and inland Southern California that is a U-factor of 0.30 or lower and an SHGC of 0.23 or lower, which in practice means dual-pane, low-E glass; the high desert and mountains need a U-factor of 0.27, and the low desert an SHGC of 0.20. The exterior door has an energy rating too: Title 24 generally calls for a door U-factor of 0.20 or lower, unless the energy report trades it off. The labels stay on until the inspector sees them.
Checked at inspection · Title 24 limits by climate zone and project · CALGreen low-VOC limits on sealants, foams and adhesives
Parts: on every window × NFRC energy label
Under CALGreen, sealants, caulks, adhesives and canned foam used on the job must meet low-VOC limits; check the label or the maker’s data sheet. The project’s energy report sets the exact window numbers, and the installer signs a form listing what went in.
Before stucco or siding covers anything, the inspector looks at the weather barrier and flashing, and checks the window labels against the energy report. Then the walls are ready for their finish.
Inspection visit ≈1 hour · Weather-barrier / lath inspection before the finish, as your city requires
That’s a weather-tight room: wrapped, every window and the door set level, plumb and square, flashed in shingle order, sealed against air and water, and built to meet California’s energy code.