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May 30, 2026
How Long Does a Home Addition Take in Seattle? Realistic 2026 Timeline
One of the first questions homeowners ask when planning a home addition is: how long will this take? The honest answer involves several phases, each with its own timeline. Here is a realistic breakdown for a typical home addition in the Seattle area in 2026.
Phase 1: Design (8-16 Weeks)
Schematic design through construction documents. Time depends on scope and revision cycles. A straightforward primary suite addition at 400 sq ft: 8-10 weeks. A full second story: 12-16 weeks.
Phase 2: Permitting (6-14 Weeks)
Standard residential addition permit review at SDCI: 6-10 weeks for initial review. One correction cycle adds 4-6 weeks. Total with one correction: 10-16 weeks. Projects in jurisdictions with faster review (Kirkland, Bellevue, Redmond) may permit in 4-8 weeks.
Phase 3: Contractor Bidding (3-5 Weeks)
Soliciting bids from 2-3 general contractors, reviewing proposals, and selecting a contractor. Note: start contractor outreach during the permit review phase to save time.
Phase 4: Construction (3-8 Months)
- Small addition (200-400 sq ft): 3-4 months
- Medium addition (400-800 sq ft): 4-6 months
- Full second story addition: 6-8 months
Total Timeline: What to Expect
Small addition, fast jurisdiction:
9-12 months from first meeting to move-in
Medium addition, Seattle permit:
12-16 months
Full second story, Seattle permit:
16-22 months
How to Speed Things Up
The biggest time savings come from working with an architect who submits complete, code-compliant drawings on the first try. Each correction cycle adds weeks. Start contractor outreach during permitting, not after. Piper Cole Architects coordinates both phases to minimize total timeline. Free consultation — call 425-753-6452.
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Free initial consultation, no obligation. Licensed architect serving Kirkland and the greater Seattle metro area since 2000.