How many ADUs can I add in Shoreline?
✓ Verified against code · August 19, 2026
Two per lot, attached or detached, within the zone's units-per-lot density: NR3 allows 3 dwellings per lot (4 near major transit), NR2 allows 4, NR1 has no unit cap.
Citation: SMC 20.40.210(A)–(B)
How current is this?
Shoreline’s ADU rules run under SMC 20.40.210 (Shoreline Municipal Code) (Ordinance 1027 (amended by Ord 1043)). Shoreline rewrote its ADU section in January 2025 (Ord 1027), then went further than the state ever asked in August 2025: Ordinance 1043 eliminated minimum vehicle parking requirements for everything, citywide. We verified this answer against primary sources on August 19, 2026, and every change we catch is logged in the changelog.
More Shoreline ADU questions
- Do I need parking for an ADU in Shoreline?
- How long does a Shoreline ADU permit take?
- How big can a Shoreline ADU be?
- Can I sell a Shoreline ADU separately?
All Shoreline ADU rules → · Compare Washington cities →
Not legal advice — lot-specific overlays can change the answer for your parcel. The citation above points at the governing code section; check it, or ask the city to confirm.