Seattle Department of Construction and Inspections: Permits and Code Enforcement

The Seattle Department of Construction and Inspections (SDCI) is the primary municipal agency responsible for regulating building activity, land use compliance, and housing and business code enforcement within Seattle city limits. The agency administers a permit system that governs new construction, alterations, demolitions, and changes of use for thousands of properties annually. Understanding how SDCI operates — which permits are required, how enforcement is triggered, and where its authority begins and ends — affects property owners, contractors, tenants, and developers throughout the city.

Definition and scope

SDCI was established as a stand-alone department following a 2016 reorganization that separated construction and inspection functions from what had been the Department of Planning and Development (DPD). The agency operates under authority granted by the Seattle Municipal Code (SMC), Washington State building statutes including RCW Title 19.27 (the State Building Code Act), and the Seattle Land Use Code. Its jurisdiction is coextensive with Seattle city limits — roughly 84 square miles of incorporated land.

SDCI administers 4 primary regulatory programs:

  1. Building permits and inspections — Review and field inspection of structural, mechanical, electrical, and plumbing work.
  2. Land use review — Discretionary review for projects requiring variances, design review, environmental review under SEPA, or shoreline permits.
  3. Housing and building maintenance — Enforcement of the Seattle Housing and Building Maintenance Code (SMC Chapter 22.200–22.208) against substandard conditions in occupied structures.
  4. Business and rental registration — Licensing of rental units and certain business premises as a condition of lawful operation.

Scope limitations and coverage: SDCI's authority does not extend to unincorporated King County, neighboring cities such as Bellevue or Renton, or state-owned facilities within Seattle that are regulated under separate Washington State Department of Labor & Industries (L&I) authority. Work performed on federally owned land within the city — such as military installations or federal buildings — falls outside SDCI jurisdiction entirely. For broader land use policy context, the Seattle Office of Planning and Community Development sets the comprehensive planning framework within which SDCI operates.

How it works

A permit application filed with SDCI passes through a defined review sequence. The complexity of that sequence depends on project type and valuation.

These require no formal plan review.

Standard plan review applies to most new construction and significant alterations. As of the fee schedule published by SDCI, permit fees are calculated on a sliding scale based on project valuation — projects valued at $1 million or more trigger a base fee plus a per-thousand multiplier established in the SDCI Fee Subtitle (SMC 22.900E).

Design review is required for multifamily buildings of 8 or more units in certain zones, and for commercial projects exceeding 12,000 square feet in designated areas. Design review adds a mandatory public meeting step before permit issuance.

After permit issuance, SDCI inspectors conduct field inspections at defined construction milestones — foundation, framing, rough mechanical, and final occupancy. Work concealed before a required inspection fails and must be uncovered at the permit holder's expense.

Common scenarios

New single-family construction: Requires a full building permit, site plan review, and at minimum 4 required inspections. If the lot is in a shoreline zone or within 200 feet of a regulated steep slope, additional environmental review under the Seattle SEPA Ordinance (SMC Chapter 25.05) applies.

Accessory dwelling unit (ADU) addition: Seattle allows both attached ADUs and detached ADUs (DADUs) on single-family lots under legislation updated in 2019. Each requires a separate building permit, and DADUs exceeding 1,000 square feet require design review in certain overlay zones. The Seattle Office of Housing administers affordability programs that may intersect with ADU projects.

Unpermitted work discovered during sale: A buyer's inspection that uncovers unpermitted additions — a finished basement, an added bathroom, a structural wall removal — typically triggers a requirement to obtain a retroactive permit. SDCI offers a "record of existing condition" permit track for some situations, but structural changes generally require full engineering documentation.

Complaint-based code enforcement: Any person may file a complaint with SDCI alleging code violations: unsafe wiring, inadequate heating in a rental unit, unpermitted construction activity. SDCI assigns complaints a priority tier based on life-safety risk. seattle.gov/sdci/about-us/complaint-based-code-enforcement)).

Decision boundaries

Two distinctions govern most permit decisions at SDCI.

Permitted use vs. discretionary approval: A project that conforms to all applicable zoning standards — height, setback, lot coverage, use type — is entitled to a permit as a matter of right once construction documents are approved. A project that does not conform requires a variance or conditional use permit, both of which involve public notice and a quasi-judicial hearing before the City's Hearing Examiner. The Seattle zoning and land use framework defines these thresholds in detail.

City authority vs. state authority: Electrical work in Seattle is inspected by Washington State Department of Labor & Industries, not SDCI. This is a frequent source of confusion. A contractor pulling a building permit from SDCI for a commercial remodel must separately coordinate with L&I for electrical inspection sign-off before SDCI will issue a final certificate of occupancy. The /index for this reference network contains additional orientation for navigating overlapping city and state regulatory roles.

For projects involving public rights-of-way, street use permits are administered by the Seattle Department of Transportation, not SDCI — even when the underlying project has an active SDCI building permit.

References

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