Seattle Zoning Explained for Homeowners: What You Can Build on Your Lot
Zoning determines what you can build on your lot — and in Seattle, the rules are more complex than most homeowners realize. Seattle’s land use code was significantly revised in recent years to add density, allow more ADUs, and create new residential zone categories. This guide explains the key zoning concepts Seattle homeowners need to understand before starting any construction project.
Seattle’s Residential Zone Types
Neighborhood Residential (NR) Zones
The 2023 rezoning consolidated Seattle’s old SF zones (SF5000, SF7200, etc.) into Neighborhood Residential categories. NR zones allow single-family homes, ADUs (one attached, one detached on most lots), and in some NR zones, small-scale multifamily.
Residential Small Lot (RSL)
RSL zones allow townhomes, rowhouses, and cottage clusters in addition to single-family homes. RSL is common in areas near frequent transit service. Projects on RSL lots have more flexibility but also more design review scrutiny.
Lowrise Multifamily (LR1, LR2, LR3)
Lowrise zones allow multifamily buildings up to 4–8 stories depending on the LR designation. Many Seattle homeowners are surprised to find their property is in an LR zone, which opens up development options beyond a single-family zone.
Key Zoning Concepts
Setbacks
In Seattle residential zones, typical setbacks are: front setback 15–20 feet, rear setback 25 feet, side setbacks 5 feet on each side. Setback exceptions apply for small structures, ADUs in certain configurations, and covered porches.
Height Limits
Standard residential zone height limits in Seattle are 35 feet to the peak. ADUs have their own limits — typically 24 feet for DADUs. Projects in Design Review have more scrutiny on height relative to neighboring properties.
Floor Area Ratio (FAR)
FAR limits the total gross floor area as a multiple of the lot area. A 5,000 sq ft lot might be limited to 3,500 sq ft of gross floor area, which significantly shapes design options. Understanding FAR is critical for custom home sizing.
ADU Rules in Seattle (2026)
- One attached ADU and one detached ADU allowed on most residential lots
- No owner-occupancy requirement (eliminated 2019)
- DADU size limit: 1,000 sq ft or 60% of primary home GFA, whichever is greater
- Both ADUs can be rented simultaneously
- Parking replacement not required when removing a garage for ADU conversion
Eastside Zoning: Kirkland, Bellevue, Redmond
If your property is in Kirkland, Bellevue, or Redmond, you are subject to that city’s land use code — each with its own zone designations and specific requirements. Piper Cole Architects is experienced in the land use codes of all Eastside cities. Our residential architecture service includes a complete zoning and feasibility analysis before design begins. See our design process to learn how we assess and navigate local regulations on every project.
Related guide: Lot Coverage, Setbacks & FAR Explained.
Frequently Asked Questions
How do I find the zoning for my Seattle property?
Look up your address using the Seattle Department of Construction and Inspections GIS map or the city parcel viewer. Your zone designation determines what you can build, how large, and how tall. An architect can pull and interpret the zoning for your specific lot.
What is FAR and how does it limit what I can build?
FAR, or floor area ratio, is the ratio of total building floor area to lot size. If your lot is 5,000 square feet and the FAR limit is 0.5, you can build roughly 2,500 square feet of floor area. FAR is one of the main constraints on how much house you can add.
What are setbacks in Seattle?
Setbacks are the minimum distances a structure must sit from the front, side, and rear property lines. They vary by zone and by structure type, and they often determine where an addition or ADU can physically go on your lot.
How tall can I build on a Seattle residential lot?
Height limits depend on your zone. Most neighborhood residential zones allow roughly 30 feet for a primary house, with some additional allowance for pitched roofs. Accessory structures and detached ADUs have lower limits.
What is lot coverage and why does it matter?
Lot coverage is the percentage of your lot that structures are allowed to cover. Exceeding it is one of the most common reasons a design has to be revised, so it is checked early in the design process.
Can I build an ADU on my Seattle lot?
Most single-family lots in Seattle can accommodate an attached ADU, a detached ADU, or both, subject to size, height, setback, and lot-coverage limits. A feasibility review confirms what your specific lot allows.
Start Here
Start Your Project
Free initial consultation, no obligation. Licensed architect serving Kirkland and the greater Seattle metro area since 2000.