Addition permits in City of Shoreline: fees, timeline & requirements (2026)

When does a home addition need a permit in City of Shoreline?

Garage conversion to ADU: use Residential Additions checklist + ADU Worksheet. SMC 20.40.210 limits ADUs to 1,200 sqft (exception: interior ADU on separate floor sharing a common roof with the primary residence may exceed 1,200 sqft). Two ADUs per lot maximum per SMC 20.40.210(A), subject to max-density in Table 20.50.020(1). Critical-area triggers (steep slopes ≥15%, wetlands, streams) require a Critical Areas Report and preapplication meeting before submittal.

From City of Shoreline's own page

“A construction permit is needed for all new construction.”

Source ↗verified 2026-05-17

Required submittals

• Permit Application and Critical Area Worksheet (Residential Additions checklist — Required Documents > Applications)
• Submittal Fee per City fee schedule (Residential Additions checklist — Required Documents > Submittal Fee)
• Building Coverage and Hardscape Calculation Worksheet (Residential Additions checklist — Required Documents)
• Civil Engineering Plans — must meet frontage requirements in SMC 20.70.320 (Residential Additions checklist — Required Documents > Civil Engineering Plans)
• Construction Documents per Construction Documents handout (Residential Additions checklist — Required Documents > Construction Documents)
• WA State Energy Code Compliance Forms, 2021 Washington State (completed); WSEC energy credits selected must be incorporated into floor plans (Residential Additions checklist — Required Documents > WA State Energy Code Compliance Forms)
• Site Plan(s) per Site Plan handout (Residential Additions checklist — Required Documents > Site Plan(s))
• Stormwater Pollution Prevention Plan (SWPPP) — Short Form for projects <5,000 sqft new/replaced hard surface AND <7,000 sqft disturbance; Ecology template for larger projects (Residential Additions checklist — Required Documents > SWPPP)
• Tree Worksheet (Residential Additions checklist — Required Documents > Tree Worksheet)
• Accessory Dwelling Unit (ADU) Worksheet — required for projects creating a new ADU or changing an existing ADU; worksheet lists additional submittal items (Residential Additions checklist — Additional Documents > ADU Worksheet)
• Arborist Report — required if work is proposed within the critical root zone of any trees to remain on site; ISA-certified arborist must assess impacts; tree protection measures must be shown on plans (Residential Additions checklist — Additional Documents > Arborist Report)
• Critical Areas Report(s) — required for projects in or near environmentally critical areas (steep slopes, streams, wetlands); preapplication meeting required prior to submittal unless waived by a planner (Residential Additions checklist — Additional Documents > Critical Areas Report(s))
• Declaration of Covenant – Stormwater Facilities — required for any project that proposes on-site stormwater facilities; refer to EDM Chapter 4.9 (Residential Additions checklist — Additional Documents > Declaration of Covenant)
• Geotechnical or Soils Report — required for projects with fill/excavation ≥500 cu yd, sites with slopes ≥15%, or certain storm drainage designs (Residential Additions checklist — Additional Documents > Geotechnical or Soils Report)
• Heating System Sizing Form — required for new residential construction and additions where total new area exceeds 750 sqft, measured cumulatively (Residential Additions checklist — Additional Documents > Heating System Sizing Form)
• Surface Water Report — required for projects proposing ≥2,000 sqft of new/replaced hard surfaces; must follow EDM Appendix C (Residential Additions checklist — Additional Documents > Surface Water Report)
• Waste Diversion Plan and Salvage Assessment — required for construction/alterations exceeding 1,000 sqft gross floor area, or when demolition work is proposed; Waste Diversion Report due before final inspection (Residential Additions checklist — Additional Documents > Waste Diversion)
• Water Availability Certificate — required when total new area exceeds 500 sqft OR new (not replacement) plumbing fixtures are proposed AND property is served by North City Water District (Residential Additions checklist — Additional Documents > Water Availability Certificate)

Inspection sequence

1. foundation/footing
2. plumbing rough-in
3. electrical rough-in
4. mechanical rough-in
5. framing
6. insulation
7. drywall
8. final

Contractor specialties needed

general, electrical-01-or-02, plumbing, mechanical

Notes & caveats

Shoreline P&CD intake is electronic-only via eTRAKiT. The Residential Additions checklist explicitly covers "conversion of existing unfinished or garage space to finished space, and new uninhabited detached spaces, such as detached garages and larger sheds" — making it the canonical scope for garage→ADU conversion paired with the ADU Worksheet. Each document must be uploaded as a separate PDF (no combined files); a 2"×3" blank space must be reserved on the cover sheet for City stamps. Per the Residential Additions checklist Rev. 8/2025: "Incomplete submittals and documents not meeting the standards listed below will not be accepted for review."

Addition permit fee estimate in City of Shoreline

Worked example for a $120,000 home addition project (building permit). Your actual fee scales with project valuation.

Apply electronically via eTRAKiT (https://www.shorelinewa.gov/government/departments/planning-community-development/permit-center-remote-services/register-for-a-professional-etrakit-account). Plan-review fees scale with valuation per City fee schedule. State Building Code Council surcharge $4.50 per building permit. Mechanical/Plumbing permits accompany the Building Permit and cannot be deferred; Electrical permits go through WA L&I (not the City). Computed from the City of Shoreline fee bracket schedule · source ↗. Impact/utility fees may apply separately.