Framing and envelope

What happens

In rough order:

1. Wall framing — bottom plate, studs, top plates, headers, openings.
2. Floor framing between levels (if 2-story).
3. Roof framing — rafters or trusses, ridge, valleys, eaves.
4. Sheathing — wall and roof, with shear panels per the structural engineer.
5. Windows and doors installed.
6. Weather-resistive barrier wrapped, taped, sealed at openings.
7. Roofing — underlayment then finished roof.

At the end of this step, the cottage is dry-in — weathertight enough that interior trades can work without rain damage.

Inspections

• Framing inspection before insulation. Verifies structural per stamped sheets, fire-blocking, hardware, hold-downs.
• Sheathing nailing inspection if shear panels are present.
• WRB / flashing inspection if local practice or your specific permit requires it.

Duration

• 1 month for a small, simple cottage with an experienced crew.
• 2–3 months is the honest range for most Seattle DADUs, accounting for weather, sub coordination, and the inevitable "we need to redo this" moment.

What goes wrong

• Window delivery. Custom windows have 8–12 week lead times. If the order isn't placed during design or early permit, framing waits.
• Weather. Roof goes on as fast as possible to get to dry-in. November–February stretches this.
• Plan changes. You see the framed shape and want to move a window. Cheap if you catch it now, expensive after sheathing.