ADU coverage, neighborhood by neighborhood

Neighborhood ADU planning — frequently asked

• Why do neighborhood pages matter for ADU planning?

  ADU rules apply at the city level but real cost drivers — lot shape, sewer slope, tree canopy, soils, alley access, single-family pattern — are neighborhood-level. A Wallingford ADU prices differently than a Magnolia ADU within the same Seattle SMC zoning because alley access changes excavation, sewer slope changes side-sewer cost, and mature trees trigger SMC 25.11 review.

• Which Seattle neighborhoods are easiest to build ADUs in?

  Easiest in 2025: Crown Hill, Bitter Lake, Pinehurst, Lake City, Rainier Beach, and Highland Park — flat lots, alley access, mature sewer infrastructure, lower tree-protection trigger rates. Hardest: Magnolia (steep), West Seattle's south slope, Madrona/Leschi (Lake Washington setbacks), and any lot inside the Lake Washington shoreline ECA.

• How many neighborhoods do you cover?

  Roughly 180 named neighborhoods across the four-county region — each with a dedicated page covering median lot size, typical ADU size band, prevailing 2025 rents, walk score, school district, transit proximity, and three sample feasibility scenarios. Pages are updated quarterly from MLS, county assessor, and our internal closed-contract data.

• Are some neighborhoods inside historic districts?

  Yes. Seattle Pioneer Square, Columbia City, Ballard Avenue, Harvard-Belmont (Capitol Hill), and Fort Lawton are designated historic districts with Seattle Historic Preservation Office review. Tacoma's Stadium and North Slope are similar. Historic review adds 6–12 weeks and constrains exterior design — your ADU page calls out the specific overlay if applicable.

• Do school district boundaries affect ADU value?

  For rental income, modestly. For owner-occupied multi-generational ADUs, significantly. We list the assigned elementary/middle/high school on every neighborhood page using the current Seattle Public Schools, Lake Washington SD, Bellevue SD, Edmonds SD, or Tacoma Public Schools assignment lookup. Boundaries can change — always re-verify the year of move-in.

• How does walkability affect ADU rent?

  Within Seattle, every 10-point increase in Walk Score correlates with approximately $85–$140/mo higher achievable ADU rent (2024 data, controlling for size). Eastside neighborhoods show a smaller premium ($45–$80/mo per 10 points) because car-ownership rates are higher. Transit proximity (within ½ mile of Link Light Rail) adds another $100–$200/mo on top.

• Can I link to a specific service from a neighborhood page?

  Yes — every neighborhood page has cross-links to garage conversion, basement ADU, and detached DADU pages with city-specific cost ranges and permit timelines pre-filled. The goal is one click from "I live in Wedgwood" to "here is what a 700 sq ft DADU costs in Wedgwood with 2025 numbers."

• Are neighborhood demographics in scope?

  We publish median household income, owner-occupancy %, and median home value from American Community Survey 5-year data, because those drive realistic rent comps and refinance LTV. We do not publish race/ethnicity composition or any data that could be misused for steering, which would violate the Fair Housing Act.