Solar Permit requirements across Washington
By Mario Bailey Last checked 2026-07-19
Requirements and size thresholds for solar permits vary by locality. The table below compares what each Washington county or city requires. Always confirm with the local office before starting.
What to know about solar permits in Washington
Solar permits in Virginia usually cover the rooftop PV system and its electrical interconnection. Costs depend on system size and your locality, and many homeowners weigh financing options such as solar loans against paying up front. Some Virginia localities use SolarAPP+ for faster automated approvals. Always use a licensed electrical or solar contractor, since the work must pass inspection.
How solar permits work, start to finish
Applying
A rooftop solar PV permit application is a combined structural and electrical plan set: a site plan and roof framing details proving the array's mounting can carry its added loads, plus a one line electrical diagram covering listed modules and inverters, disconnects, and the rapid shutdown design. Utility interconnection is a separate approval that runs in parallel with the permit.
- Both a building permit and a separate electrical permit are required, since the array must be designed and installed to the residential code's solar provisions and to the National Electrical Code (IRC R324.3).
- The plan set identifies listed equipment: PV modules listed to UL 1703 (or both UL 61730-1 and UL 61730-2), and inverters listed to UL 1741, with grid-tied inverters listed for utility interaction (IRC R324.3.1).
- Structural drawings show that the roof framing is designed to structurally support the array and withstand the gravity loads it adds (IRC R324.4.1).
- The site plan lays out roof access pathways at least 36 inches wide, plus a ridge setback sized to how much of the roof the array covers, so firefighters retain pathways and ventilation access (IRC R324.6.1, IRC R324.6.2).
- The one line electrical diagram shows the rapid shutdown method and the location of its single initiation device, since one control point must bring all system conductors down to safe levels (NEC 690.12, NEC 690.56(C)).
- Interconnecting the array to the utility grid at a defined point of connection is a separate application process from the local building or electrical permit and must be approved before the system can operate (NEC 705.12).
- Some permitting offices route applications through SolarAPP+, an automated review platform that checks the plan set against code requirements and issues eligible permits instantly (DOE SolarAPP+).
Inspections and close-out
Inspectors verify the installed array against the approved plans, and some agencies run a rough check of roof attachments and penetrations while they are still exposed before the wiring and roofing close them in. The final inspection confirms rapid shutdown, disconnects, grounding, and required labels are installed correctly, and the system cannot be energized until the utility separately approves interconnection.
- Where an agency runs a rough or pre-inspection, it checks the array's roof penetrations while they are still exposed, confirming they are flashed and sealed (IRC R324.4.3).
- The inspector confirms whether rapid shutdown is required, how it is accomplished, and that it is properly identified (NEC 690.12, NEC 690.56(C)).
- PV disconnecting means must be permanently marked and installed where they are readily accessible, which the inspector confirms in the field (NEC 690.13).
- Bonding and grounding of the array, including every exposed non current carrying metal part and the grounding electrode system, is checked before sign off (NEC 690.43, NEC 690.47).
- At the service equipment, the inspector looks for the required rapid shutdown placard, a labeled diagram showing the initiation device's location in the specified colors and letter sizes (NEC 690.56(C)).
- Utility interconnection is inspected and approved separately from the local building department's sign off, and the system cannot be energized until both approvals are in hand (NEC 705.12).
General practice; pick your county below for its specific rules, fees, and portal. Sources: IRC 2021 R324 (Solar Energy Systems) and NEC 2020 Article 690 (Solar Photovoltaic Systems) and Article 705 (Interconnected Power Production Sources), NEC 2020 Article 690 (690.12 rapid shutdown, 690.13 disconnects, 690.43/690.47 grounding, 690.56 labeling) and IRC 2021 R324.4.3 (roof penetrations).
Swipe sideways to see thresholds and confidence.
| Locality | Permit required? | Typical threshold | Confidence |
|---|---|---|---|
| Bellevue | Conditional | electrical permit required for all solar systems; building permit not required for rooftop single-family systems with dead load under 3.5 lbs per sq ft and panels no more than 18 inches above roof surface | Confirmed on official page |
| Clark County | Yes | Separate SOL permits are required for ground mounted units or panels mounted on existing buildings; in new construction the solar panels are included in the NHC or ADS permit. | Confirmed on official page |
| King County | Conditional | roof-mounted solar PV panels weighing less than 4 pounds per square foot on residences do not require a building permit; heavier installations require a permit | Confirmed on official page |
| Pierce County | Yes | Not specified | Confirmed on official page |
| Seattle | Yes | Not specified | From an official source |
| Snohomish County | Conditional | ground-mounted residential solar PV systems never need a building or mechanical permit; roof-mounted residential PV on a detached single-family house is exempt from a building/mechanical permit only if total dead load is 3.5 lbs per sq ft or less (up to 4.5 lbs per sq ft for frameless panels on a 3:12 or steeper slope, or 5 lbs per sq ft for frameless panels on a 5:12 or steeper slope), panels are mounted 18 inches or less above the roof surface, and an electrical permit has already been issued; a separate electrical permit through WA L&I is always required regardless | From an official source |
| Tacoma | Yes | Not specified | Confirmed on official page |
| Thurston County | Conditional | Residential rooftop solar PV systems need no county permit; ground-mounted and commercial systems require county permits, and every solar project needs a state L&I electrical permit. | Confirmed on official page |
| No localities match your filter. | |||
Ready to move on your solar permit?
Hire it out
Before you sign, ask the contractor:
- Who pulls the permit, you or me, and is the permit fee included in the bid?
- Which inspections will this job need, and who meets the inspector on site?
- Is your contractor license active in this locality, and under which business name?
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