What will utilities cost on a Federal Way ADU?
✓ Verified against code · August 20, 2026
More than you might expect, because Federal Way has no water or sewer utility of its own. Service comes from Lakehaven, Tacoma Water, Midway Sewer or Highline Water depending on where you are, and a septic property needs King County Public Health sign-off before permitting. The city warns that ADU plumbing load can force a water meter or service-line upsizing, or a separate meter, and a detached unit needs its own sewer connection permit.
Citation: City Bulletin #048
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
- Do I need parking for a Federal Way ADU?
- How big can a Federal Way ADU be?
- How tall can a Federal Way ADU be?
- What do impact fees cost on a Federal Way ADU?
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.