City of Seattle Land Use Code: Zoning, Permits, and Appeals

The Seattle land use code, found in Title 23 of the Seattle Municipal Code, controls what you can build on a given property, how big it can be, how it must look, and what you have to do to get it approved.¹ The Seattle Department of Construction and Inspections (SDCI) administers the code and reviews permit applications for safety, environmental impact, and zoning compliance.² The rules changed substantially in January 2026, so the first thing to check on any project is whether your lot’s zone still matches what you remember.

What Changed in 2026

Seattle adopted the One Seattle Plan and began implementing its rezones in early 2026. Legislation effective January 21, 2026 replaced the old single-family designation with a new category called Neighborhood Residential (NR) and also rezoned areas that had been designated Residential Small Lot.³ NR zones now allow a wider variety of housing types on lots that previously could only hold one detached house.

A second package, Centers and Corridors, followed later that month. It creates rezones in Neighborhood Centers, expands Urban Centers, and allows more apartments and condos along frequent transit routes, along with adjustments to Lowrise and Midrise development standards.³ Both pieces of legislation comply with Washington House Bill 1110, which requires cities to allow greater housing density near transit. If you own property in Seattle, confirm your current zoning designation before you rely on anything you remember from prior years.

Zoning Categories

Title 23 establishes every zoning classification used in the city, from residential neighborhoods to industrial waterfront areas.⁴

Residential

Neighborhood Residential (NR), the January 2026 replacement for single-family zoning, now allows a broader range of housing. Lowrise zones step up from there. Lowrise 1 encourages townhouses, rowhouses, and small apartment buildings. Lowrise 3 permits taller apartment buildings with a base height limit of 40 feet, rising to 50 feet under the Mandatory Housing Affordability program.

Commercial

Neighborhood Commercial (NC) zones cover mixed-use districts with ground-floor retail and housing above. NC1 covers small-scale convenience retail with most commercial uses capped at 10,000 square feet. NC2 targets moderately sized, pedestrian-oriented shopping areas with commercial uses up to 25,000 square feet. NC3 covers the largest shopping districts with varied business sizes and strong transit access.⁵ Height limits in commercial zones range from 30 to 200 feet depending on the zone suffix.

Industrial

General Industrial 1 (IG1) protects marine and rail-related industrial areas by restricting unrelated retail and commercial uses. Industrial Commercial (IC) takes a different approach, mixing light manufacturing and research with a wider range of employment uses.⁶ The city deliberately preserves industrial land to keep trade and manufacturing employers in place.

Development Standards Every Project Meets

Regardless of zone, every building project has to meet dimensional standards that control how much of a lot you can build on.

Floor Area Ratio (FAR) limits total building square footage relative to lot size. A FAR of 2.0 on a 2,500-square-foot lot lets you build up to 5,000 square feet of floor space, whether as a two-story building covering the whole lot or a four-story building covering half. Height limits vary widely: residential zones typically allow 30 to 40 feet, commercial zones range from 30 to 200 feet, and parts of the downtown core allow 400 feet or more.⁵ Exceeding base limits generally requires participation in the Mandatory Housing Affordability program or a variance.

Setbacks buffer your building from neighbors and keep a consistent street appearance across a block. Open space requirements keep part of the site unbuilt. The exact numbers depend on your zone and building type, so pull the code for your designation early in design rather than after drawings are done.

Mandatory Housing Affordability

Mandatory Housing Affordability (MHA) requires most new commercial, residential, and live-work projects to contribute to affordable housing. You can choose the performance option, which builds affordable units into the project, or the payment option, which sends a per-square-foot fee to the Seattle Office of Housing fund.⁷

Under the performance option, residential projects outside downtown typically must make between 5% and 7% of units affordable, depending on whether the area is classified as a high-, medium-, or low-cost market. Commercial projects outside downtown dedicate 5% of square footage. MHA applies after a rezone increases maximum height or FAR, or sets a different zoning designation for the property.⁸

Payment rates adjust annually on March 1 based on the Consumer Price Index. For March 1, 2026 through February 28, 2027, commercial payment rates run from roughly $11 to $33 per square foot depending on zone.⁸ On larger projects the difference between the two options can be substantial, so run both numbers during feasibility.

Design Review

Design Review shapes the appearance of new multifamily and commercial buildings. Its purpose is to encourage better design and site planning so new development fits into neighborhoods while still allowing creativity.⁹ Administrative Design Review carries a minimum fee of $2,800; full Design Review starts at $5,600 for the first 20 hours of staff time, with additional hours billed at $280 per hour.¹⁰

Some projects are temporarily exempt from Design Review through April 2026, including those building on-site affordable units under MHA and qualifying low-income housing projects.¹¹ A separate temporary exemption for projects in certain urban centers and industrial areas that include research labs or are at least half residential runs through November 2027.

Overlays That Can Override the Base Zone

Environmentally Critical Areas

SMC 25.09 imposes additional restrictions on properties with sensitive geological or ecological features. If your parcel contains any mapped Environmentally Critical Area (ECA), you must comply with the rules for that hazard type.¹² The designated categories are:

Geologic hazard areas: landslide-prone sites, liquefaction-prone soils, peat-settlement areas, seismic hazard zones, steep slope erosion areas, and volcanic hazard zones
Flood-prone areas
Wetlands
Fish and wildlife habitat conservation areas: streams, riparian corridors within 100 feet of watercourses, and state-designated priority habitats
Abandoned landfills

ECA rules commonly require setbacks or buffers, geotechnical reports, stormwater management, and sometimes outright prohibition of construction in the most hazardous spots. Properties within the Shoreline District follow an older, separate set of ECA regulations rather than the 2017 update that applies elsewhere.¹² SDCI’s GIS mapping tool shows which ECAs affect a parcel; check it before design work begins.

Shoreline District

The Shoreline District is an overlay under SMC Chapter 23.60A. When shoreline rules conflict with the underlying zone, the shoreline rules win.¹³ This chapter implements the state Shoreline Management Act, which requires cities to protect shoreline natural resources, preserve the character of the waterfront, and provide public access to publicly owned shoreline areas.¹⁴ The district generally covers all land within 200 feet of the shoreline, plus hydrologically connected wetlands and all submerged land. Developers typically have to show that a project protects aquatic habitat, addresses public access, and offsets adverse environmental impacts.

Tree Protection

SMC 25.11 governs tree removal, and the rules tighten when a property is being developed. Requirements depend on the tree’s tier (based on size and species), the property’s zoning, and whether construction is planned. Trees are classified as “exceptional” when they exceed a species-specific diameter threshold measured four and a half feet above the ground.¹⁵

Exceptional trees generally must be retained unless keeping them would prevent the project from reaching the development potential allowed by the zone, even after available departures from development standards are considered. In Neighborhood Residential and RSL zones, an exceptional tree may be removed only if protecting it during construction would prevent the property from achieving its maximum allowed lot coverage.¹⁵ Survey the site’s trees before you finalize a design; discovering an exceptional tree afterward often forces expensive rework.¹⁶

Accessory Dwelling Units

Seattle allows both attached accessory dwelling units (AADUs, sometimes called in-law apartments) and detached accessory dwelling units (DADUs, commonly called backyard cottages). An AADU is a separate unit inside the main house; a DADU is a freestanding unit elsewhere on the property. Some lots may be large enough for four or more total units, but only two of them may be ADUs.¹⁷

Under legislation that took effect in mid-2025, the height limit for ADUs is 32 feet in Neighborhood Residential and RSL zones, with above-ground floor area capped at 1,000 square feet. Multifamily zones also allow 32-foot-tall ADUs, with an additional 350 square feet beyond the previous floor area cap. These limits can be exceeded when converting existing space within a principal residence. Seattle removed its owner-occupancy requirement in 2019, so you do not have to live on-site to build or rent out an ADU.¹⁷

Getting a Permit

Documentation to Assemble

A land use application to SDCI is a technical package. You need a certified land survey by a licensed professional establishing precise property boundaries and topography, plus a detailed site plan showing proposed structures, utility connections, and landscaping. SDCI publishes specific site plan requirements in Tip 103, and the plan must meet standard scales and formatting for electronic review.¹⁸

Projects above certain size thresholds trigger the State Environmental Policy Act (SEPA) checklist covering air, water, traffic, and wildlife habitat impacts, which the city uses to decide whether a full Environmental Impact Statement is needed.¹⁹ Depending on scale and location, drainage studies, soil stability reports, and traffic impact analyses may also be required.

The Master Use Permit Process

Most land use approvals go through the Master Use Permit (MUP) system. A Pre-Application Site Visit is required for most land use permits, all new construction permits, grading applications, projects with ground disturbance over 750 square feet, and any project in the shoreline or on property with mapped steep slopes.¹⁸

Applications are submitted electronically through the Seattle Services Portal.²⁰ Staff screen for completeness, then the city issues public notice. For Type II MUPs, SDCI makes the decision, which can be appealed to the Hearing Examiner or the Shoreline Hearings Board. Type III permits (subdivisions) go to the Hearing Examiner after a public hearing. Type IV actions like rezones go to City Council after notice, an SDCI recommendation, a public hearing, and a Hearing Examiner recommendation.²¹

Fees

The general MUP minimum fee covers the first 10 hours of review, which works out to $2,800 in 2026. Full Design Review, if triggered, adds a separate minimum of $5,600 for the first 20 hours. Council conditional uses, rezones, and other Type IV and V approvals also start at $5,600. Hours beyond the minimum are billed at $280 per hour, and SDCI invoices for review time as it accumulates. A $345 correction fee may be charged for each additional correction cycle caused by applicant delays.¹⁰ Complex projects requiring both a MUP and Design Review can easily run into five figures in review fees alone.

Appeals and Penalties

If SDCI denies your permit or imposes conditions you dispute, you can appeal to the Seattle Hearing Examiner. The appeal must be received before 5:00 p.m. on the stated appeal deadline and must include a $120 filing fee.²² The deadline is printed on your decision letter, and missing it forfeits your appeal right, so mark it the day you receive the decision.

Enforcement typically begins with a complaint. If an inspector confirms a violation, the property owner gets a notice explaining the violation, required corrections, any fines owed, the compliance deadline, and any right to appeal.²³

Penalties escalate with time. The standard civil penalty is up to $150 per day for each violation during the first 10 days of noncompliance, then up to $500 per day for each violation beyond 10 days until compliance is achieved. Certain violations carry higher penalties: an unauthorized dwelling unit in a residential zone triggers a $5,000 fine per extra unit, though that drops to $500 if the unit is removed or legalized before the compliance deadline. Willful or bad-faith violations can result in criminal penalties of up to $5,000 per occurrence.²⁴ These penalties are cumulative, so a $500-per-day violation left unaddressed for months can grow expensive fast.

1
Seattle Department of Construction and Inspections. Land Use Code
2
Seattle Department of Construction and Inspections. Seattle Department of Construction and Inspections
3
Seattle Office of Planning and Community Development. One Seattle Plan
4
Seattle Municipal Code. Seattle Municipal Code Title 23 – Chapter 23.30 Zone Designations Established
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Seattle Department of Construction and Inspections. Commercial Zoning Summary
6
City of Seattle. Seattle Industrial Zoning Summary
7
Seattle Office of Housing. Mandatory Housing Affordability
8
Seattle Department of Construction and Inspections. Mandatory Housing Affordability (MHA) Program
9
Seattle Municipal Code. Seattle Municipal Code Title 23 – 23.41.002 Purpose
10
Seattle Municipal Code. Seattle Municipal Code Title 22 – 22.900C.010 Land Use Fees
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Seattle Department of Construction and Inspections. Design Review Exemptions
12
Seattle Department of Construction and Inspections. Environmentally Critical Areas (ECA) Code
13
Seattle Municipal Code. Seattle Municipal Code Title 23 – Chapter 23.60A Seattle Shoreline Master Program Regulations
14
Washington State Department of Ecology. Shoreline Management Act
15
Seattle Department of Construction and Inspections. Tree Protection Regulations
16
Seattle Department of Construction and Inspections. Tree Removal
17
Seattle Department of Construction and Inspections. Accessory Dwelling Unit
18
Seattle Department of Construction and Inspections. How Do You Get a Permit
19
Washington State Department of Ecology. SEPA Checklist Guidance
20
Seattle Services Portal. Permits, Licenses and Regulatory Compliance
21
Seattle Department of Construction and Inspections. Land Use / Master Use Permit – Overview of MUP
22
Seattle Department of Construction and Inspections. How to Appeal a Decision
23
Seattle Department of Construction and Inspections. What Should I Do if I’m Cited
24
Seattle Municipal Code. Seattle Municipal Code Title 23 – Chapter 23.90 Enforcement of the Land Use Code