How tall can a Federal Way ADU be?
✓ Verified against code · August 20, 2026
30 ft above average building elevation, and unusually, a detached ADU is allowed to be taller than the primary house. That is well above the 24 ft floor HB 1337 sets.
Citation: FWRC 19.200.180
How current is this?
Federal Way’s ADU rules run under FWRC 19.200.180 (Accessory Dwelling Units) (Ordinance 25-1016 §§30–31). Federal Way amended its ADU standards for HB 1337 in Ordinance 25-1016, effective June 3, 2025 — just ahead of the state's June 30 deadline. It is one of the few cities in this ledger still requiring an off-street parking space for an ADU outside the transit waiver, and the city has no water or sewer utility of its own, which turns utility connections into a real budget line. We verified this answer against primary sources on August 20, 2026, and every change we catch is logged in the changelog.
More Federal Way ADU questions
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All Federal Way 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.