Submit the SDCI Addition/Alteration permit

Which permit type

A second-story addition is filed as an Addition or Alteration to Existing Building building permit (not the new-SFR permit). Two filing tracks:

1. Standard building permit — for any addition with full plan review. This is what you'll use.
2. Subject-to-Field-Inspection (STFI) — for very small alterations. Not applicable to a second-story addition.

What's in the submittal

A typical second-story addition submittal contains:

• Architectural drawings (existing and proposed plans, elevations, sections).
• Structural drawings + calculations (stamped).
• Energy code compliance narrative.
• Site plan (from the boundary survey).
• Existing and proposed gross floor area calc (FAR).
• A copy of the SDCI Tip 314 checklist if substantial-alteration trigger is in play.
• The lead/asbestos report from step 0.4.
• Geotech report (if Phase 1 produced one).

How fees work

SDCI charges based on project valuation, with 75% of the building permit fee due at intake and 25% at issuance. Other reviewing departments (Side Sewer, Energy, etc.) bill their own fees on top.

For a typical Seattle second-story addition:

• Building permit: $5,000–$15,000 total.
• Intake (75%): $3,750–$11,250.
• Issuance (25%): $1,250–$3,750.

If the review goes long beyond standard hours, SDCI bills additional time at the published hourly rate (currently around $292/hr).

Timeline

• Intake: 1–2 weeks.
• First review: 4–8 weeks for straightforward projects, 8–12 weeks for complex ones.
• Correction loops: see step 3.5.

How you submit

Through the Seattle Services Portal. Your designer typically handles the portal mechanics and the back-and-forth with reviewers — that's part of their fee.