Learning · ADU cost literacy
ADU cost factors
What drives accessory dwelling unit cost in the North Sound — typology, utilities, and AHJ path. Not a bid; official links only for fees/standards.
ADU-specific drivers
- Typology — detached new, attached, garage conversion, or ADU within a new residence.
- Foundation and utility runs — sewer/water/power distance and upsizing.
- Fire separation, egress, and sound/privacy detailing for attached or stacked units.
- Kitchen and bath wet cores — full dwelling MEPs, not a guest suite refresh.
- Site constraints — setbacks, trees, critical areas, parking, and alley/ROW access.
- City standards & permits — Edmonds ECDC paths and MyBuildingPermit ADU applications; Seattle SDCI fees when applicable.
- Owner vs rental use assumptions that change finish durability (still not Board ROI).
- Inspection sequencing and temporary occupancy logistics on tight lots.
Edmonds ADU hub · ADU readiness checklist · fees context: Seattle SDCI fees · MyBuildingPermit
ADU cost factors FAQ
Does the Board publish ADU construction prices?
No. ADU cost depends on detached vs conversion, utilities, foundation, fire separation, parking/access rules, and city standards. Official Edmonds standards live in city code and handouts — not Board fee tables.
Where do I find Edmonds ADU rules?
Start with the Board Edmonds ADU hub and official ECDC / MyBuildingPermit links there. Confirm live code before freezing design.
Are national ADU Cost vs Value numbers local bids?
No. Treat them as national study context only. Your parcel, utility runs, and AHJ fees control the real number.
Official resources
Outbound links to government portals only. The Board of Project Stewardship does not issue permits or licenses. Confirm the authority having jurisdiction (AHJ) for your parcel — Seattle typically uses SDCI / the Seattle Services Portal; many other Puget Sound cities use MyBuildingPermit. Always re-verify contractors at WA L&I Verify before hiring.