What do Olympia's ADU park impact fees cost?
✓ Verified against code · August 19, 2026
Olympia charges a park impact fee of $3.92 per square foot of habitable ADU space, with a minimum charge of $3,187.93, under a rate that took effect July 1, 2026. The fee is always capped at 50 percent of whatever the principal unit would owe, so a second unit never costs more in park fees than half the main house's rate. ADUs remain exempt from school impact fees entirely, regardless of size or configuration.
Citation: Ord 7470
How current is this?
Olympia’s ADU rules run under OMC 18.04.060 (Olympia Municipal Code) (Ordinance 7444 (amended by Ord 7457)). Olympia adopted its combined HB 1110/1337 package in November 2025 — about five months after the state deadline — making its rules the freshest of the region's major cities. Its ADU liberalization runs deep, though: zero parking has been the rule here since 2019, and the city's ADU history dates to 1995. We verified this answer against primary sources on August 19, 2026, and every change we catch is logged in the changelog.
More Olympia ADU questions
- Can I sell my Olympia ADU separately from my house?
- Do I need parking for an Olympia ADU?
- Is there a tax break for building an ADU in Olympia?
- How many ADUs can I build, and how big?
- When did Olympia's current rules take effect?
- Does Olympia offer pre-approved DADU stock plans?
All Olympia 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.