Sammamish, WA Solar Energy: Panel Permits (2026)
Key Facts
- Permit required
- Electrical permit under SMC 16.20.197, any voltage
- Plan review
- Mandatory for solar PV, SMC 16.20.255(2)(f)(ix)
- Engineer stamp
- Required for complex/unique-design installations
- Permit validity
- 2 years from issuance
- No exemption
- Solar PV not on the permit-free work list
Summary
Solar photovoltaic systems in Sammamish need more than a routine electrical permit. SMC 16.20.255(2)(f)(ix) names solar PV among the installations that trigger mandatory electrical plan review, meaning an engineer-level review of your system plans before the permit center will issue the permit under SMC 16.20.197.
(f) Plan Review Required. Electrical plan review is required for all new or altered electrical projects in the following occupancies and/or installations including but not limited to: ... (ii) Installations in occupancies except one- and two-family dwellings where a service or feeder rated 100 amperes or greater is installed or altered or if more than 100 amperes is added to the service or feeder. (iii) All work on electrical systems operating at/over 600 volts. (iv) All commercial generator installations or alterations. (v) All work in areas classified as hazardous locations by the NEC. (vi) If 60 percent or more of luminaires change. (vii) Installations of switches or circuit breakers rated 400 amperes or over except for one- and two-family dwellings. (viii) Wind-driven generators. (ix) Solar photovoltaic systems. (x) Any proposed installation which cannot be adequately described in the application form.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance O2026-598, and legislation passed through August 18, 2026).
Full Breakdown
28 RCW, for the installation, alteration, repair, replacement, modification or maintenance of all electrical systems, wire and electrical equipment regardless of voltage, a category that covers a rooftop or ground-mounted solar photovoltaic array. 255(2)(f) requires full electrical plan review for a specific list of installations, including but not limited to hospitals and other institutional facilities, services or feeders of 100 amperes or more added to non-single-family occupancies, work at or over 600 volts, commercial generators, hazardous locations, projects changing 60 percent or more of luminaires, switches or breakers rated 400 amperes or over, wind-driven generators, and, at item (ix), solar photovoltaic systems specifically. 255(2)(a). 235.
Violations & Fines
Installing a solar array without the required electrical permit and plan review exposes the installer or owner to a stop work order and special investigation fee under SMC 16.20.355, added on top of the permit and plan review fees. Continuing the installation after a stop work order draws civil penalties under Chapter 23.100 SMC, and the building official can require re-inspection or removal of installed materials to confirm the system was installed correctly.
Frequently Asked Questions
Do I need a permit for rooftop solar panels in Sammamish?
Why does my solar installer talk about 'plan review' for a residential system?
How long does a solar electrical permit stay valid?
Sources & Official References
Other rules in Sammamish
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Panel Permits in Nearby Cities
How other cities in King County handle panel permits.