DADU feasibility · Northgate & Maple Leaf
Building a DADU in Northgate & Maple Leaf
Northgate and Maple Leaf pair generous lots with light-rail proximity, which changes what the density rules allow.
This profile is measured from City of Seattle open data across 3,665 parcels in Northgate/Maple Leaf — not estimated, and not the same numbers as any other neighborhood on this site.
Lot sizes in Northgate & Maple Leaf
Lots run large — most are above 5,000 sq ft, with a substantial share above 7,200. Combined with proximity to the Northgate link station, parts of this area sit inside the transit thresholds that raise the allowed unit count.
Parcel counts by lot size, Northgate/Maple Leaf. Source: King County parcels via Seattle's ADUniverse dataset.
19% of parcels here are under 5,000 sq ft and 81% are 5,000 sq ft or larger — a high 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 Seattle repealed the old 3,200 sq ft minimum lot area for a DADU, so small lots are no longer excluded; they are simply governed by the floor-area budget instead.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
Stable and largely flat, with the highest peat settlement-prone share in this set. Peat is a foundation-cost issue, not a permit blocker, but it belongs in the budget from day one.
Northgate & Maple Leaf 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
Side sewer, water and electrical capacity
24% of buildings here predate 1940 and 42% 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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02
Protected trees
Tree canopy covers 29.8% of Northgate & Maple Leaf (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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03
Liquefaction and soil conditions
8.7% of Northgate & Maple Leaf 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.
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04
Slope and landslide-prone ground
3.9% of Northgate & Maple Leaf is mapped as steep slope (40% or greater) and 0% 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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05
Physical fit on a small lot
19% 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.
Zoning and utilities
Zoning mix
- SF 50002,607 parcels
- SF 7200549 parcels
- LR2166 parcels
- LR381 parcels
- LR2 RC60 parcels
86.3% of parcels are Neighborhood Residential or Residential Small Lot; 8.7% 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 194024%
- 1940 – 197542%
- After 197530%
Mid-century stock with mostly separated storm and sanitary sewer, which simplifies drainage review compared with the older combined-sewer parts of the city.
Northgate & Maple Leaf DADU questions
Can I build a DADU in Northgate & Maple Leaf?
In almost all cases the zoning allows it. 86.3% of parcels in Northgate & Maple Leaf 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 Northgate & Maple Leaf?
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 81% of Northgate & Maple Leaf parcels at 5,000 sq ft or larger, most owners here have room to reach the cap rather than being cut off by it.
What is most likely to block a DADU in Northgate & Maple Leaf?
Side sewer, water and electrical capacity — 24% of buildings here predate 1940 and 42% 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.
Do I need a feasibility study before designing a DADU in Northgate & Maple Leaf?
You are not required to have one. But the checks that decide feasibility — setbacks against the existing house, FAR headroom, tree tiers, mapped critical areas, side sewer condition, and construction access — are all cheaper to answer before you commit to an architect or a plan set than after. In Northgate & Maple Leaf specifically, start with the side sewer and the panel — on flat, stable ground like this, utilities are what most often reset the budget.
Next step
Run these checks on your own Northgate & Maple Leaf lot.
This page tells you what Northgate & Maple Leaf looks like as a whole. The Seattle DADU Pro Guide walks your specific address through the same review — setbacks and FAR headroom, tree tiers, mapped critical areas, side sewer and panel capacity, the permit roadmap, and a scoring template you fill in yourself.