Concrete Permits in Seattle: Which Projects Need One

Concrete permit requirements vary by city and project type. Some projects can move ahead without permits, while others require plan review and inspections. In Seattle, permits are split mainly between two agencies: the Seattle Department of Construction and Inspections (SDCI) for work on private property, and the Seattle Department of Transportation (SDOT) for the public right-of-way. Use this hub to find the guide for your project, understand the common triggers, and plan your timeline.

Permit guides by project

Each guide below covers one type of project in depth, with links to the official city sources:

• Driveway approach and curb cut permits - read this when your driveway work reaches the curb cut, apron, or sidewalk crossing in the public right-of-way.
• Stormwater rules for driveways and patios - read this when you will add or replace 750 square feet or more of paving, which brings an SDCI grading permit and drainage review.
• Sidewalk repair for property owners - read this when the public sidewalk next to your lot is damaged or you have an SDOT repair notice under SMC 15.72.
• Retaining wall permits - read this for any wall over 4 feet measured from the bottom of the footing, any wall holding back a surcharge, and any wall on a parcel with a critical area.
• ECA review for concrete projects - read this when the SDCI map shows a steep slope, landslide-prone, peat, wetland, riparian, or other environmentally critical area on or near your lot.
• Basement and structural permits - read this for underpinning, new footings, egress windows, or any other work on load-bearing supports.
• Bellevue driveway permits - read this for a Bellevue driveway, where a right-of-way (TG) permit and clearing and grading thresholds apply.
• Everett driveway permits - read this for an Everett driveway, where a Site Work permit, apron width limits, and stormwater review at 2,000 square feet apply.

Which Seattle agency handles what

Work	Agency and typical rule
Patios and concrete slabs on grade; walks, platforms, and driveways under 18 inches above grade	SDCI: usually no permit, unless the property is in an environmentally critical area SDCI
Adding or replacing 750 sq ft or more of paving	SDCI: grading permit (or grading review within a building permit) and drainage review SDCI Paving
Retaining walls	SDCI: no permit only if 4 feet or lower from footing bottom, not on an ECA parcel, not surcharged, and no risk to adjoining property SDCI
Foundations, footings, underpinning, and other load-bearing work	SDCI: permit required regardless of project size SDCI
Curb cuts, driveway aprons, and public sidewalks	SDOT: Street Use permit before work starts (curb cuts can also be reviewed within an SDCI construction permit) SDOT AG 1001
Drain lines connected to the sewer or storm system	Seattle Public Utilities: side sewer permit SPU

Projects that often require permits

• New or expanded driveways: especially if the work impacts the curb, sidewalk, or right-of-way, or adds or replaces 750 square feet or more of paving.
• Structural slabs or foundations: new builds, additions, or major structural work.
• Retaining walls: taller walls, walls supporting loads, and walls on critical-area parcels.
• Commercial access upgrades: ADA ramps, loading areas, or site improvements.
• Drainage changes: projects that redirect water, modify grading, or connect to a side sewer.

Common inspection checkpoints

Inspectors may review base preparation, reinforcement placement, and overall form layout before the pour. A final inspection may occur after the concrete is placed and access points are finished. In the right-of-way, SDOT starts with a job start notification and an initial inspection and ends with a final inspection. SDOT

How a contractor helps with compliance

A local contractor can advise on documentation, coordinate inspection timing, and align the work with city standards. If you are planning a driveway, patio, or foundation project, ask about permit requirements early.

Plan for added lead time

Permits and inspections can add days or weeks to the schedule depending on project complexity. SDCI posts current review times against its goals on its construction permit performance page and notes that an applicant's total time is roughly twice the days in City control. SDCI Review our project timeline and curing guide to build a realistic schedule around weather and approvals.

Frequently asked questions

Which concrete projects need permits in Seattle?

Permits are typically required for foundations and other work on load-bearing supports, retaining walls over 4 feet (or surcharged, or on a critical-area parcel), right-of-way work such as sidewalks, curb cuts, and driveway approaches. Work that would otherwise be exempt can need a permit on a property in an environmentally critical area. SDCI usually doesn't require a permit for patios and slabs on grade or driveways under 18 inches above grade, but it requires a grading permit once you add or replace 750 sq ft or more of paving.

SDCI vs SDOT — what is the difference?

SDCI (Seattle Department of Construction & Inspections) handles permits on private property — foundations, retaining walls, grading, structural work. SDOT (Seattle Department of Transportation) handles Street Use permits in the right-of-way — sidewalks, curb cuts, driveway approaches, anything between the property line and the street. A curb cut that is part of a building project is reviewed within the SDCI construction permit.

How much do Seattle concrete permits cost?

It depends on the project. SDCI fees depend on project size and complexity, the value of the work, review time, and inspection fees, and SDCI publishes an annual fee estimator. SDOT Street Use permits combine issuance fees, hourly review and inspection charges, and use fees for the right-of-way area you occupy. Geotechnical and structural engineering fees are separate.

How long does permit review take?

SDCI publishes current review times on its Construction Permit Performance page; for single-family additions and alterations the goal is 30 calendar days in City control, and the applicant's total time is roughly twice that City time. SDOT doesn't publish one fixed time, but each Street Use permit step shows a targeted date in the Seattle Services Portal. Plan for delays during peak season.

What inspections happen on a permitted concrete project?

It depends on the permit. SDCI inspections happen at the stages the permit requires, often footings or forms before concrete is placed, then a final. SDOT Street Use work starts with a job start notification and initial inspection and ends with a final inspection. The contractor typically coordinates the holds and required documentation.

Sources

• SDCI – Do You Need a Permit?
• SDCI – Paving
• SDCI – Retaining Walls & Rockeries
• SDCI – How Much Will Your Permit Cost?
• SDCI – Construction Permit Performance
• SDOT – AG 1001: SDOT Permits for Development Projects
• SDOT – Street Use Inspections
• Seattle Public Utilities – Side Sewer Permits

Get help from a Seattle concrete contractor

Seattle Concrete can help you evaluate permit needs and plan a smooth installation. Explore our concrete services in Seattle to get started, or see retaining wall installation costs if a wall is part of the plan.