Change Summary
It has been only half a year, and we are already back with another post about the updated Land Use Code. What are the changes in the permanent legislation (Council Bill 120993) for Neighborhood Residential zones (formerly known as Single Family zones)? And how does this compare with the existing and interim legislation?
We know folks probably aren’t tracking Seattle’s current land use (zoning) code changes as closely as we are, so we wanted to help you understand what is happening. Here is the Full Code as amended.
Below is a quick summary of the differences between the old Land Use Code, the interim code, and the new—and hopefully final—code. We have highlighted the new code sections in red for clarity. Please treat this as a guide only; we are simplifying some of the technicalities for the sake of clarity. We must also acknowledge the fast-paced nature of these changes, so our initial interpretations may vary from the final application. It is always smart to engage an architect who can help you navigate the nuances for your particular site.
Before we get started, here are a few key terms:
Lot Area: Simply the total square footage of the land.
Dwelling Unit: A unit that a person or family inhabits. This could be a house, an Accessory Dwelling Unit (ADU), an apartment, etcetera.
Stacked Flats: The new code focuses quite a bit on "stacked flats." These are multi-story residential buildings where each dwelling unit is contained within a single floor and stacked vertically. They often share a central entrance or have individual street-level doors for each unit.
Cottage Housing: While not explicitly named in the new code, this refers to a housing type where dwelling units are oriented to face a central courtyard and we have taken the liberty to add that term for clarity below.
Zoning Changes
The new legislation simplifies the zoning map by removing the previous designators for neighborhood residential zones (NR1, NR2, NR3) and combining them into a single Neighborhood Residential (NR) zone.
These designators were effectively carryovers from past regulations—formerly SF-5000, SF-7200, and SF-9600—where the number dictated the minimum square footage required for a single home. These were renamed to NR1, NR2, and NR3 in preparation for this shift, but the new code moves away from these rigid lot-size districts entirely.
Additionally, the short-lived Residential Small Lot (RSL) zone will now be converted to Lowrise 1 (LR1). Please note that the LR1 zone is not included in this specific summary.
Floor Area (SMC 23.44.050)
Formerly SMC 23.44.011
Floor Area is measured from the interior face of the exterior walls. We often explain to clients that while interior walls and stairs count toward this limit, the thickness of the exterior walls does not.
The maximum allowable floor area is expressed as a ratio, commonly referred to as FAR (Floor Area Ratio). Just like lot coverage, this ratio is multiplied by the total lot area to calculate the maximum floor area permitted for all buildings located on a particular site.
Old Floor Area (Prior to June 2025): 0.5 of the lot area
Exemptions:
• Areas below grade (less than 4’ between grade and ceiling)
• Accessory Dwelling Units
• 500 square feet of detached accessory structure (think shed or garage) or 250 square feet for an attached garage
Interim Floor Area (June 2025):
• 1 dwelling unit per 4000 square feet or greater: 0.6 of lot area
• 1 dwelling unit per 2,201-4000 square feet: 0.8 of lot area
• 1 dwelling unit per 2,200-1,601 square feet: 1.0 of lot area
• 1 dwelling unit per 1,600 or less: 1.2 of lot area
New Floor Area (Feb 2026):
• 1 dwelling unit per 4000 square feet or greater: 0.6 of lot area
• 1 dwelling unit per 2,201-4000 square feet: 0.8 of lot area
• 1 dwelling unit per 2,200-1,601 square feet: 1.0 of lot area
• 1 dwelling unit per 1,600 or less: 1.6 of lot area / 1.8 for stacked flats
Bonus cottage housing type
Development on lots located within a frequent transit service area (see Seattle GIS) that consists entirely of attached or detached dwelling units in structures that are less than three stories and that are arranged on up to three sides of a common ground-level amenity area equal to at least 20% of the lot area that includes usable, contiguous community green space and trees.
• 1 dwelling unit per 1,600 or less: 1.8 of lot area
Bonus for stacked flats that are both:
1. Within one quarter mile of and elementary or secondary school
2. At least 25% of the stacked dwelling units have a minimum of three bedrooms and a minimum floor area of 1,050 square feet.
• 1 dwelling unit per 2,201-4000 square feet: 1.0 of lot area
• 1 dwelling unit per 2,200-1,601 square feet: 1.2 of lot area
• 1 dwelling unit per 1,600 or less: 2.0 of lot area
Bonus for stacked flats that meet one of the following:
1. Retain a tier 1 tree
2. Retain two tier 2 trees
3. Meet a Green Factor score of 0.6
• 1 dwelling unit per 1,600 or less: 2.0 of lot area
Exemptions:
• Areas below grade (less than 4 feet between grade and ceiling)
• Common walls separating individual attached dwelling units
• Square footage of dwelling units that are Type A (accessible) as defined by the Seattle Building Code
Overall this is a slight increase in floor area, particularly for housing types the council has been motivated to push like stacked flats.
Floor plans showing floor areas
Maximum Height (SMC 23.44.070)
Formerly SMC 23.44.012
This is simply the highest a structure can be on a lot.
Old Maximum Height (Prior to June 2025): 30 feet with a 5 foot bonus given to gable roofs with a pitch of 4:12 or greater
New Maximum Height (June 2025): 32 feet with a 5 foot bonus given to gable roofs with a pitch of 4:12 or greater
New Maximum Height (Feb 2026):
32 feet except developments noted below.
42 feet for cottage housing and stacked flats as described below.
• Development with 3 or more principal dwelling units and a 20 foot front yard setback (cottage housing).
• Stacked dwelling units that are within one quarter mile of and elementary or secondary school and at least 25% of the stacked dwelling units have a minimum of three bedrooms and a minimum floor area of 1,050 square feet.
• Stacked dwelling units that meet a Green Factor score of 0.6 or higher
• Structures on lots that retains a Tier 1 or Tier 2 tree and achieve a tree point score resulting in a 10% canopy coverage
Additional bonus height is permitted as follows
• 5 foot bonus given to gable roofs with a pitch of 4:12 or greater
• 3 foot bonus given to shed & butterfly roofs (4 foot max at eave)
• 4 foot for parapets associated with flat roofs
The updated code increases the maximum height by 2 feet and provides a bonus for stacked flats and cottage housing developments.
Image showing maximum building height for this home
Lot Coverage (SMC 23.44.080)
Formerly SMC 23.44.010
Lot coverage is anything that covers the ground/grade of your lot. We like to tell clients anything that covers the ground at 36 inches or higher counts towards lot coverage. There are a few exceptions like fences and the first 36 inches of eaves, but overall, the 36-inch rule above grade plane is a great way to think of it.
Old Lot Coverage (Prior to June 2025):
• Lots that are equal or greater than 5000 square feet: 35% of the lot area
• Lots that are less than 5000 square feet: 15% of lot area + 1000 square feet
New Lot Coverage (June 2025):
• 35% of the lot area or 15% of lot area + 1000 square feet for lots less than 5000 square feet for the Primary Dwelling unit and any attached accessory dwelling unit. (no change)
• 50% of the lot area for any lot that has two or more detached dwelling units (primary dwelling unit, house, and detached accessory dwelling unit).
New Lot Coverage (Feb 2026):
50% of the lot area excluding lot area that is within the following:
• Riparian corridors
• Wetlands and their buffers
• Submerged lands and areas within the shoreline setback
• Designated non-disturbance area in a steep slope
60% of the lot area for stacked flat and cottage housing types as follows.
• Development with 3 or more principal dwelling units and a 20 foot front yard setback (cottage housing)
• Stacked dwelling units.
Notable Exceptions to lot coverage include:
• Square footage of Type A (Accessible) Units including any non-accessible unit above or below.
The code increased lot coverage for all developments and added area bonuses for both stacked flats and cottage house types.
It should also be noted that the exception that allowed for the lot coverage area to include half of the alley along a rear yard is not presented in version of the code reviewed.
Image showing lot coverage in red
Setbacks (SMC 23.44.090)
Formerly called Yards and SMC 23.44.014
The term 'yards' has been removed and replaced with 'setbacks' to reflect how most people understand the concept. A setback is a restriction prohibiting the placement of a structure within a certain distance from the property line.
Old Yards (Prior to June 2025): :
Front: 20 feet or the average of neighbors (which can’t be less than 15 feet)
Side: 5 feet
Rear: 25 feet or 20% of the lot depth
There are a lot of exceptions we’re excluding from this summary.
New Yards (June 2025):
Front:
• Lots with one or two dwelling units: 15 feet
• Lots with three or more dwelling units: 10 feet
Rear:
• Lots not abutting an alley with one or two dwelling units: 15 feet
• Lots not abutting an alley with three or more dwelling units: 10 feet
• Lots abutting an alley: no rear yard
Side: 5 feet (no change)
Similar exceptions, with an additional exception for Queen Anne Boulevard as submitted by Rob Kettle to exclude that right of way from these requirements.
New Setbacks (Feb 2026):
Front:
• Lots with one or two dwelling units: 15 feet
• Lots with three or more dwelling units: 10 feet
Rear:
• Lots not abutting an alley with one or two dwelling units: 15 feet
• Lots not abutting an alley with three or more dwelling units: 10 feet
• Lots under 5000 square feet within frequent transit service areas: 5 feet
• Lots abutting an alley: no rear yard
Side:
• 5 feet average, 3 feet minimum
• Lots under 5000 square feet within frequent transit service areas: 3 feet
Queen Anne Boulevard remains exempt from the setback requirements listed above; please refer to the specific code section for those regulations.
While there are fewer changes compared to the interim legislation of June 2025, the new rules represent a significant shift in setbacks compared to the older code.
Site plan showing yards
Amenity Areas (SMC 23.44.110)
Amenity areas must be provided for all developments in NR Zones. The requirements are as follows:
Attached and detached units: 20% of lot area
Stacked Flats: 25% of the lot area (reduced to 20% if each unit includes a private balcony)
Exceptions: No amenity area is required for:
• A new dwelling unit added to a dwelling unit that existed as of January 1, 1982
• A new dwelling unit added to a multifamily residential use existing as of October 10, 2001
• Development that retains a Tier 2 tree or achieves a tree point score equivalent to 10% canopy coverage.
This is a new requirement for neighborhood residential zones, though it mirrors language previously required in multifamily zones.
Overall, we are excited to see the impact these changes will have on our city and hope they result in more affordable housing to meet our community's needs. If you have any questions about these updates, please feel free to contact us.