ADU Ledger

How close to the lot line can my DADU sit?

✓ Verified against code · August 19, 2026

Five feet from side and rear lines — but only if it's a stand-alone DADU. Combine it with a garage or other structure and standard setbacks apply, so the configuration choice matters.

Citation: SMC 21.04.030.C conditions (4), (7)

How current is this?

Sammamish’s ADU rules run under SMC 21.05.010.C(5) / 21.04.030.C (Sammamish Municipal Code) (Ordinance O2024-578). Sammamish's Title 21 rewrite (Ord O2024-578) took effect January 1, 2025 — six months ahead of the state deadline. Beware the city's own DADU handout: last revised September 2023, it still shows an 18-ft height limit, one-DADU cap, and two-space parking rule, all long repealed. We verified this answer against primary sources on August 19, 2026, and every change we catch is logged in the changelog.

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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.