The rule: electrical always, building sometimes
SDCI's Tip 420 (updated 14 July 2025, read 23 October 2026) says "You need to get an electrical permit for all solar electric systems." A building permit is not needed when the installer confirms the system meets all of these:
| SDCI criterion for skipping the building permit | Limit |
|---|---|
| Where | A rooftop of a single-family house |
| Mounting | "engineered and designed for solar electric systems" |
| Roof | "made from lightweight material such as shingle" |
| Height | Panels no more than 18 inches above the roof, nothing above the highest point of a pitched roof |
| Weight | Total dead load no more than 5 pounds per square foot |
| Point load | No more than 50 pounds on a single framing section |
| Also | Manufacturer's attachment specs, specified flashing, land use (setbacks, height) and fire code met |
A building permit is needed when a rooftop system misses any of those, when it is a ground mount on its own structure, or when "The solar electric system is part of building alterations or additions, valued over $6,000 (not including the value of solar equipment)". A heavy tile roof or a racking system over the weight limits can tip the job into a building permit.
What it costs
Table D-15 of SDCI's 2026 Fee Subtitle (effective 1 January 2026) lists "Renewable Energy Systems (photovoltaic, wind power generation, etc.) Below 12 kW: $438.00". Tip 420 explains it: for systems up to 12 kW the fee is "1.5 times the 'base fee'", and the 2026 base fee is $292; over 12 kW it is 3 times the base fee and the system "must be submitted for plan review".
| Item | 2026 fee |
|---|---|
| PV system below 12 kW (includes its branch circuits) | $438.00 |
| PV system over 12 kW | Plan review, 3 × $292 base fee |
| Administrative fee, every permit | $55.48 |
| Service upgrade 150 to 200 A, if needed | $292.00 |
| Technology fee on all SDCI fees | 5% |
A typical 8 kW roof system: $438 + $55.48 = $493.48, about $518 with the technology fee. Add $292 if the panel needs a 200-amp service upgrade.
How to apply
- The installer applies online in the Seattle Services Portal. Up to 12 kW is an over-the-counter (OTC) permit with "a one-line electrical diagram and catalogue cuts for system installation" (Tip 420). SDCI's Electrical Permit page still says online without plan review applies to systems "under 7.7KW"; the 2026 fee table and Tip 420 both use 12 kW. If your system is between the two, ask SDCI's electrical technical support on (206) 684-5383 which applies.
- Batteries: tick "Energy Storage System?" on the application for the three-page ESS questionnaire. "Home battery systems do not require Seattle Fire Department (SFD) review unless they exceed 40 kWh."
- Fire access: on a single-ridge roof, panels must leave "two, 3-feet-wide unobstructed access pathways from the eave to the ridge", unless the house is sprinklered or the array meets the Tip's size exception.
- Inspection after installation; keep the approved set on site.
- Interconnection: City Light's Interconnection Application and Agreement is "conditional on the final approval of your electrical permit". Don't switch on before both.
Professionals need a Washington electrical contractor's license and a Seattle business license; owners may do their own work on a house they own and occupy (SDCI). Check the installer on L&I Verify.
What 2,013 Seattle solar and battery permits show
| Measure | Seattle solar and battery |
|---|---|
| Permits on homes, October 2023 to September 2026 | 2,013 |
| Firms | 81 |
| Firms with a permit in the last 12 months | 57 |
| Usual filed value | $15,040 |
| Middle half of firms' usual value (33 firms) | $5,000 to $19,200 |
| Permits carrying a value | 92.1% |
| Completed (permits a year or more old) | 97.1% |
| Usual days from issue to completion | 43 |
| 10th-percentile firm (10+ permits) | 91.1% |
| Five busiest firms' share | 59.7% |
| Firms matched to an active L&I record | 87.7% |
| Busiest / quietest month | October (index 132) / February (74) |
Seattle solar installers finish their permits: 97.1% completed, and even the 10th-percentile busy firm completed 91.1%. So the useful comparisons are price and volume. The middle half of firms' usual jobs runs $5,000 to $19,200; the trade mixes battery and add-on permits with full arrays, so compare a full-array quote with the upper half rather than the usual value. Filings peak in October (index 132) and dip in February (74), so signing in late winter puts the install ahead of the autumn rush.
See every Seattle solar installer by permits completed →
Related
Other electrical work: Seattle electrical permit. Choosing the installer: hiring a solar installer. Checks: Seattle contractor license lookup, Seattle building permit search. Rules elsewhere: do I need a permit for solar panels. Prices: solar panel installation cost. Counts by year and month: Seattle permit statistics.
What this does not tell you
Our Seattle solar trade includes battery permits, which pulls the usual value down. The filed value is the applicant's estimate, not the invoice, and it may or may not include the equipment. Owner permits name no firm. License status is our name match to L&I's file.
How we know this
The permit rules, building-permit criteria, fee method, battery and interconnection rules are quoted from SDCI's Tip 420 (updated 14 July 2025), the fee from Table D-15 of SDCI's 2026 Fee Subtitle, and the licensing rule and 7.7 kW wording from SDCI's Electrical Permit page, all read 23 October 2026. Counts are SDCI solar and battery permits on Seattle homes, October 2023 to September 2026; "completed" uses permits a year or more old. License status is our name match to Washington L&I.
Numbers come from City of Seattle (SDCI) building, trade and electrical permits on single-family and duplex homes (the city's open-data exports), data through October 17, 2026. Nobody paid to be on this page and nobody can.
Questions
- Do I need a permit for solar panels in Seattle?
Yes, an electrical permit for every solar electric system. A building permit is needed only when a rooftop system on a house falls outside SDCI's criteria: an engineered solar mount on a lightweight roof such as shingle, panels no more than 18 inches above the roof, no more than 5 pounds per square foot, and no more than 50 pounds on any single framing member.
- How much is a solar permit in Seattle?
For a system below 12 kW, $438 under Table D-15 of SDCI's 2026 Fee Subtitle (1.5 times the $292 base fee), plus the $55.48 administrative fee and a 5% technology fee, about $518 in all. Systems over 12 kW go to plan review at 3 times the base fee plus the administrative fee.
- How long does a solar permit take in Seattle?
A typical system up to 12 kW is an over-the-counter electrical permit, applied for online with a one-line diagram and catalog cuts. The usual Seattle solar and battery permit in our file was completed 43 days after issue.
- Do I need a permit for a home battery in Seattle?
Yes, it goes on the electrical permit: SDCI's application has an 'Energy Storage System?' checkbox that opens a three-page questionnaire. Home batteries do not need Seattle Fire Department review unless they exceed 40 kWh.
- When can I turn my Seattle solar system on?
After City Light approves it. SDCI says Seattle City Light requires an Interconnection Application and Agreement, which is conditional on the final approval of your electrical permit.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- Do I need a permit for solar panels? Yes: the rule in 12 cities, and how fast they close
- Albuquerque building permit search: how to look up permits on an address
- Do I need a solar permit in Albuquerque? Building and electrical permits, the engineer triggers and the fee
- Do I need a solar permit in Anaheim? The online small-rooftop permit, the 10 kW line and the City utility
For one city
- Tip 420: Solar Energy Systems and Solar-Ready Roofs for Residential Buildings (updated July 14, 2025) — SDCI (accessed 2026-10-23)
- 2026 Fee Subtitle (SMC 22.900), Table D-15 Electrical Permit Fees — SDCI (accessed 2026-10-23)
- Electrical Permit — Seattle Department of Construction and Inspections (accessed 2026-10-23)
- Seattle Services Portal — City of Seattle (2026-10-23)
- Verify a Contractor, Tradesperson or Business — Washington L&I (2026-10-22)