DADU feasibility · Queen Anne
Building a DADU in Queen Anne
Queen Anne packs 8,117 parcels onto a hill, with 61% under 5,000 sq ft and only 19.4% of homes detached. Its 9.7% steep slope and 14.7% potential-landslide mapping make it the hardest common case in the city.
Queen Anne is the hardest common case in Seattle: small lots, steep ground, and dense multifamily zoning all in one place. This profile is measured from City of Seattle open data across 8,117 parcels in Queen Anne — not estimated, and not the same numbers as any other neighborhood on this site.
Lot sizes in Queen Anne
More than half of Queen Anne's parcels are under 5,000 sq ft and a quarter are under 3,200. It also carries the largest Lowrise share in this set, so a meaningful number of 'DADU' questions here are really redevelopment questions.
Parcel counts by lot size, Queen Anne. Source: King County parcels via Seattle's ADUniverse dataset.
61% of parcels here are under 5,000 sq ft and 39% are 5,000 sq ft or larger — a low share among the 18 areas profiled here. Seattle repealed the old 3,200 sq ft minimum lot area for a DADU, so small lots are no longer excluded; they are simply governed by the floor-area budget instead.
What the ground looks like
The hill's flanks carry substantial steep-slope and potential-slide mapping. Grade change across a single lot is the defining Queen Anne constraint — it drives access, foundation type, and whether equipment can reach the rear yard at all.
Queen Anne against the median of the 18 Seattle areas profiled here. Hazard layers clipped to the neighborhood boundary; canopy is area-weighted by census block group.
What decides feasibility here, in order
Ranked by what this neighborhood's own measurements say — not a generic checklist.
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01
Slope and landslide-prone ground
9.7% of Queen Anne is mapped as steep slope (40% or greater) and 14.7% as potential landslide area, against Seattle medians of 7.7% and 4.4% across the areas profiled here. Land inside an Environmentally Critical Area under SMC 25.09 triggers additional review and, in practice, a geotechnical report before design.
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02
Side sewer, water and electrical capacity
43% of buildings here predate 1940 and 9% were built between 1940 and 1975. Older stock means older side sewers and smaller electrical services — the two utility findings that most often reset a DADU budget.
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03
Physical fit on a small lot
61% of parcels here are under 5,000 sq ft. Lot size no longer disqualifies a DADU, but on a tight lot the lot-wide FAR and lot-coverage budget — which ADU floor area now counts toward — usually binds before setbacks do.
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04
Protected trees
Tree canopy covers 23.6% of Queen Anne (Seattle median here: 26.9%). Seattle's tree code (SMC 25.11) protects trees by tier, and a Tier 2 tree with its root protection area falling across your rear yard can move or shrink a cottage even on a large lot.
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05
Liquefaction and soil conditions
6.9% of Queen Anne sits on mapped liquefaction-prone soils (Seattle median here: 8.7%). This rarely stops a project, but it changes foundation design and belongs in the budget before you price a build.
Zoning and utilities
Zoning mix
- SF 50004,568 parcels
- LR31,109 parcels
- LR11,076 parcels
- LR2327 parcels
- SM-UP 85212 parcels
56.3% of parcels are Neighborhood Residential or Residential Small Lot; 32.6% are Lowrise. Zone labels reflect the parcel dataset's legacy single-family categories, which map into today's Neighborhood Residential zone under Ordinance 127376.
Housing age
- Before 194043%
- 1940 – 19759%
- After 197541%
Old stock, tight sites, and long uphill utility runs. Queen Anne is the neighborhood where construction access should be checked before anything else.
Queen Anne DADU questions
Can I build a DADU in Queen Anne?
In almost all cases the zoning allows it. 56.3% of parcels in Queen Anne sit in Neighborhood Residential or Residential Small Lot zoning, where detached accessory dwelling units are permitted, and Seattle removed both the old minimum-lot-size test and the owner-occupancy requirement. The real question is whether a compliant cottage physically fits your lot and whether utilities can serve it.
How big can a DADU be in Queen Anne?
The citywide caps apply: 1,000 sq ft of gross floor area for an ADU with up to two bedrooms, or 1,200 sq ft with three or more. On top of that, your lot has a single FAR and lot-coverage budget shared with the existing house — which is what actually limits most projects. With 61% of Queen Anne parcels under 5,000 sq ft, the cap is usually academic here — the lot-wide budget runs out first, and a 600–800 sq ft cottage is the realistic target.
What is most likely to block a DADU in Queen Anne?
Slope and landslide-prone ground — 9.7% of Queen Anne is mapped as steep slope (40% or greater) and 14.7% as potential landslide area, against Seattle medians of 7.7% and 4.4% across the areas profiled here. Land inside an Environmentally Critical Area under SMC 25.09 triggers additional review and, in practice, a geotechnical report before design.
Read these before you spend anything on Queen Anne
Free, written for Seattle's code, and picked from Queen Anne's own numbers rather than a generic list.
All 20 guides and notes → · every record we can read on a Seattle parcel →
Next step
Get the report for your address in Queen Anne.
This page tells you what Queen Anne looks like as a whole. The customized feasibility report runs your specific address through the same review — setbacks and FAR headroom, tree tiers, mapped critical areas, side sewer and panel capacity, and a permit path — measured from City records and reviewed by a person. Prefer to self-study? The Pro Guide covers the same rules.