Thurston County, WA Solar Energy: Panel Permits (2026)

Item 17 of the exemption list in § 14.17.030, which amends International Building Code [A]105.2, excuses "residential photovoltaic roof top solar energy installations in compliance with IRC section M2301.2" from Thurston County's building-permit requirement. That exemption is conditional: it only reaches installations that meet the structural, fastening, and fire-clearance standards IRC M2301.2 sets for rooftop solar, so an installation that departs from those specifications, or one on a commercial or multifamily roof outside the residential code's scope, does not qualify.

An installation that falls outside IRC M2301.2's compliance path needs a permit under § 14.17.030's general rule, [A]105.1: the property owner or an authorized agent must apply to the Community Planning and Economic Development Department and secure a permit before mounting the array, and the fee for that permit follows the schedule adopted under § 14.17.050. Even an exempt installation is not excused from every county requirement: § 14.17.030 notes that exempt work can still need review under other chapters or under Titles 15 through 25 if the mounting affects roofing, structural load, or setbacks.

Installing a non-compliant rooftop system, or one that needs a permit and does not have one, exposes the owner to § 14.17.060's enforcement provisions: building without a permit under [A]105.1 is a class 1 civil infraction under Chapter 7.80 RCW, with each day of the violation treated as a separate infraction, backed by a misdemeanor penalty under [A]114.5 of up to $1,000, up to ninety days in jail, or both.