Roof line. Full second story (gable, hip, shed)? Partial second floor with a dormer? Each has different cost and different code implications. Stair location. New second-floor stair has to land somewhere on the existing first floor. Often the single biggest constraint on the floor plan. Bedroom and bath layout upstairs. Massing relative to neighbors. Seattle doesn't have formal neighborhood design review for most additions, but visible second-story pop-ups attract neighbor attention. A designer who has done these will think about how the addition reads from the street.

2.3 Schematic design + neighborhood-fit review · Second-story addition in Seattle: SDCI permits, cost, timeline

Schematic design + neighborhood-fit review

The designer produces three to five floor-plan and massing options. You pick one, refine it together, and end the step with a single concept that fits the lot, the neighborhood, and your budget.

Who

Designer, Architect, Homeowner

How long

4-8 weeks

Cost

Included in design fee

You end up with

Approved schematic design package (plans, elevations, basic massing)

Schematic ("first-pass") design is the fun phase — you'll spend a lot of evenings staring at floor plans wondering whether to put the stair here or there. The trick is keeping the iteration disciplined enough that you land on one direction before structural engineering needs it.

What "schematic" means

The first design pass. Floor plans, exterior elevations, basic massing — enough to see the shape of the addition and how it sits on the existing house. Not engineered yet; not detailed enough to build from.

What gets explored

Roof line. Full second story (gable, hip, shed)? Partial second floor with a dormer? Each has different cost and different code implications.
Stair location. New second-floor stair has to land somewhere on the existing first floor. Often the single biggest constraint on the floor plan.
Bedroom and bath layout upstairs.
Massing relative to neighbors. Seattle doesn't have formal neighborhood design review for most additions, but visible second-story pop-ups attract neighbor attention. A designer who has done these will think about how the addition reads from the street.

Schematic outputs

1/4"-scale floor plans of existing + new.
Exterior elevations on all four sides.
A section cut at the new stair.
A renderings or massing study (often a SketchUp model).

How many revisions

Typically two or three rounds before you settle on a direction. The designer will manage this against the hours in their agreement; if you push past three rounds expect an additional fee.

When this ends

You sign off on a single direction. The next step (structural engineering, step 2.4) needs that single direction to engineer to.