San Mateo County

A city address is usually permitted by the city, not the county — but not always, and some authorities keep building and hand electrical to someone else. Getting this wrong costs the whole submittal, because every requirement below belongs to whoever actually holds jurisdiction. Check the overlays in the same pass: an HOA, a historic district, a windstorm certification or a system-size cap can reshape the design, and all of them are cheaper to find now than after the array is laid out.

• Is this authority the AHJ for residential solar at this address? Yes 95% · adopting ordinance (County Ordinance Code Title 10)
• What does this authority permit itself, and what does it delegate? Both — building and electrical, issued by Planning and Building as one building permit 85% · adopting ordinance
• Is a permit required for a residential rooftop PV system? Yes 95% · adopting ordinance
• Is there a separate electrical permit, or is it combined? Combined — one building permit covers the electrical work 75% · fee schedule (Building Service Fee Schedule, updated 01/29/2026, effective 1 Apr 2026)
• Is a HOA or architectural approval required first? No 95% · adopting ordinance
• Is a wind or windstorm certification required? No separate wind or windstorm certification 65% · published checklist
• Is a Specific Use Permit or Council approval ever required? Yes, exceptionally. Title 10 s.10.60.070: the Building Official may require a use permit 'if the Building Official finds, based on substantial evidence, that the small residential rooftop solar energy system could have a specific, adverse impact upon the public health and safety', with written notice to the applicant. 'Specific, adverse impact' is defined as a significant, quantifiable, direct and unavoidable impact based on objective written health or safety standards existing when the application was deemed complete. Separately, Coastal Zone, Design Review, Resource Management and Planned Agriculture districts always require planning review first to determine the level of processing. 90% · adopting ordinance
• Is there a system-size cap on residential generation? No cap on generation size, but two path caps: the statutory expedited path is limited to 10 kW AC nameplate (or 30 kW thermal), and the Symbium instant-approval path is limited to rooftop systems up to 38.4 kW AC. Above 38.4 kW AC, or ground-mounted, or commercial, the application goes through the Accela online permit center. 80% · ordinance + permit page

Several authorities require the electrical permit to be pulled by a licensed electrician, or require the contractor to be registered with them BEFORE applying. Registration is not same-day. This is second on the list rather than fourth because it is the step most likely to stop the job before the drawings matter.

• Who is allowed to pull the electrical permit? Either — licensed contractor or homeowner (owner-builder) 65% · department page
• Must the contractor be registered with this authority before applying? No separate pre-registration with the County found; state CSLB licensing is what is verified 55% · department page
• Is a homeowner permitted to self-install and self-permit? Yes 65% · department page

Almost everywhere wants a site plan, a one-line or three-line electrical diagram, equipment cut sheets with listings, and a structural attachment detail. Build it against the published checklist rather than the last jurisdiction you worked in — the checklist is what the reviewer marks against.

• What documents make up a complete submittal? Site Plan; Floor Plan; Single Line Electrical Drawing with Warning Labels; Warning Placard; Electrical Wiring Details; Load Calculations; Manufacturer Specification as applicable. For the expedited path additionally: Eligibility Checklist for Expedited Solar Photovoltaic, a completed Solar PV Standard Plan (Simplified Central/String Inverter or Micro-inverter/ACM version), and the completed Structural Criteria for Residential Rooftop Solar Energy Installations worksheet. 90% · published checklist / permit page
• How many copies, and in what format? PDF, submitted online — no paper copy count; 'Complete sets of plans in PDF format shall be submitted online when applying for a building permit' 85% · department page
• Is a site plan required, and what must it show? Yes. For the expedited solar path the roof/site plan must show the module and anchor layout, and a separate diagram must show the roof layout of all panels and modules, the clear access pathways, the approximate location of the electrical disconnecting means, and the roof access points. General plot-plan content (owner, job address, APN, property dimensions, structure sizes and distance to property lines, utility connections, drainage, north arrow and scale, easements, trees) is set out on the Building Permit Requirements page. 90% · published checklist (Eligibility Checklist for Expedited Solar Photovoltaic)
• Is a one-line / three-line diagram required? Yes 95% · permit page
• Are string and conductor calculations required? Yes 85% · standard plan form
• Is a structural PE stamp required, and at what threshold? Not required if every item on the Structural Criteria worksheet is answered YES. If one or more items are NO: 'Attach project-specific drawings and calculations stamped and signed by a California-licensed Civil or Structural Engineer.' 88% · published checklist (Structural Criteria for Residential Rooftop Solar Energy Installations)

Most authorities now take the whole application through a portal, and several states cap or constrain what a residential solar permit may cost. Check whether plan check is billed separately before you quote the job.

• Which permit portal does this authority use? Two portals: Symbium (instant, automated, for eligible residential solar and ESS) and Accela Citizen Access at aca-prod.accela.com/smcgov (the County's Online Permit Center) for everything else 95% · portal landing page
• Can the whole application be completed online? Yes 90% · department page
• What does a residential solar permit cost? $536 base + $18 per kW for each kW above 15 kW, plus a non-refundable Application Filing Fee ($60 Easy Review / $298 Moderate Review), plus surcharges of 2% document storage + 4% technology + 5% legal counsel on Planning and Building fees, plus a $25 service fee if issued through Symbium 80% · published fee schedule
• How is the fee calculated? Tiered — flat base with a per-kW adder above a threshold 85% · published fee schedule
• Is there a separate plan-check fee? No separate plan-check fee for solar 60% · published fee schedule

Interconnection is a separate process from the permit and usually the longer pole. Where the utility does not depend on the permit being issued, running both at once is the single biggest saving available on a residential job.

• What is the stated plan-review turnaround? Real-time / instant for Symbium-eligible systems (no manual review). Otherwise: completeness determination generally within 5 days, and plan-check agencies 'generally must complete their reviews and either pass or provide comments for resubmittal within 30 days'. AB 2234 statutory floor: completeness within 15 days, review complete within 30 days for projects of 25 units or fewer. 80% · department page
• How long is an issued permit valid before it expires? Expires if work is not commenced within 12 months of issuance, or if work is suspended or abandoned for 180 calendar days (Title 10 s.10.04.110). Miscellaneous permits — a list including 'electrical services' and 'similar work' — are valid 180 days from issuance (s.10.04.120.4). 65% · adopting ordinance
• Which utility handles interconnection here? Pacific Gas and Electric (PG&E) for interconnection; Peninsula Clean Energy (now trading as WestLight Energy) is the community choice aggregator supplying generation 65% · permit page (utility resource link)
• Where does the utility sit in the sequence? Parallel, with PTO strictly after — the County permit and the utility interconnection are independent tracks. Title 10 s.10.60.060: 'Approval of an application does not authorize connection to the electrical grid, which must be obtained from the applicable utility.' PG&E's sequence is: prepare interconnection agreement, install, get city/county inspection, then permission to operate. 75% · adopting ordinance + utility page

The NEC edition a jurisdiction enforces is often a cycle behind the newest one published, and local amendments sit on top of it. Rapid shutdown, conductor sizing and labelling all change between editions, so the edition in force is the first thing to establish, not the last.

• Which NEC edition is in force? 2020 (NEC 2020, in force as the 2022 California Electrical Code, Title 24 Part 3) 70% · adopting ordinance
• Which building code edition is in force? 2022 California Building Code (Title 24 Part 2) and 2022 California Residential Code (Title 24 Part 2.5) 70% · adopting ordinance
• Which fire code edition is in force? 2022 California Fire Code (Title 24 Part 9), together with Sections 305, 307, 308, 311 and Appendices B, C, D, K, L and N 70% · adopting ordinance
• Are there local amendments to any of the above? Yes — extensive local amendments (fire apparatus access, sprinklers, EV charging infrastructure, energy and green building reach codes). But NONE of them touch the solar PV provisions. 85% · adopting ordinance
• What is the installation judged against? The 2022 California Electrical Code as adopted, plus 'all applicable safety and performance standards established by the California Electrical Code, the Institute of Electrical and Electronics Engineers, and accredited testing laboratories such as Underwriter's Laboratories and, where applicable, rules of the Public Utilities Commission' 85% · adopting ordinance

Ridge setbacks and roof access pathways are fire-service requirements and they constrain the array layout. They are the most common cause of a redesign after the fire department comments on a plan set.

• What ridge setback and access pathways are required? No local amendment — the unamended state rules apply (2022 California Fire Code solar PV provisions and CRC R331). The County's own requirement is stated only as a pass/fail item: 'Clear access pathways are provided' and 'a diagram of the roof layout of all panels, modules, clear access pathways, and an approximate location of electrical disconnecting means and roof access points'. 70% · published checklist + adopting ordinance

Which rapid-shutdown rule applies follows directly from the NEC edition in force, and the initiation device has to be at a location the fire service can reach and identify. This is inspected, and it is labelled.

• Is rapid shutdown required, and to which NEC edition? Required to the NEC edition in force — 690.12 of NEC 2020 as adopted in the 2022 California Electrical Code 60% · adopting ordinance (code edition in force)

The NEC sets a baseline for permanent markings at the service equipment and the disconnecting means. On top of that, an authority may specify its own wording, and the utility may specify more again. Where any of them writes its own text, a generic off-the-shelf label set will not pass — this is the detail most often fixed on a return visit.

• Which placards does this authority require at the service equipment? Per the County's Solar PV Standard Plan, markings required at these components: (1) at the inverter output connection OCPD — 'WARNING / INVERTER OUTPUT CONNECTION; DO NOT RELOCATE THIS OVERCURRENT DEVICE' (CEC 705.12(D)(7); not required if the panelboard is rated not less than the sum of the ampere ratings of all overcurrent devices supplying it); (2) at the main service panel — 'WARNING / DUAL POWER SOURCES / SECOND SOURCE IS PHOTOVOLTAIC SYSTEM / RATED AC OUTPUT CURRENT - ___ AMPS AC / NORMAL OPERATING VOLTAGE ___ VOLTS' (CEC 690.54 & 705.12(D)(4)); (3) at the AC disconnect — 'PV SYSTEM AC DISCONNECT / RATED AC OUTPUT CURRENT - ___ AMPS / AC NORMAL OPERATING VOLTAGE ___ VOLTS' (CEC 690.54); (4) at the DC disconnect — 'PV SYSTEM DC DISCONNECT / RATED MAX POWER-POINT CURRENT - ___ ADC / RATED MAX POWER-POINT VOLTAGE - ___ VDC / SHORT CIRCUIT CURRENT - ___ ADC / MAXIMUM SYSTEM VOLTAGE - ___ VDC' (CEC 690.53); (5) 'WARNING: PHOTOVOLTAIC POWER SOURCE' marked on junction/combiner boxes and on conduit every 10 feet (CEC 690.31(E)(3)); (6) at the disconnect — 'WARNING / ELECTRIC SHOCK HAZARD / DO NOT TOUCH TERMINALS / TERMINALS ON BOTH LINE AND LOAD SIDES MAY BE ENERGIZED IN THE OPEN POSITION' (CEC 690.17); (7) 'WARNING / ELECTRIC SHOCK HAZARD / IF A GROUND FAULT IS INDICATED, NORMALLY GROUNDED CONDUCTORS MAY BE UNGROUNDED AND ENERGIZED' (CEC 690.5(C), normally already present on listed inverters); (8) ungrounded systems only — 'WARNING / ELECTRIC SHOCK HAZARD. THE DC CONDUCTORS OF THIS PHOTOVOLTAIC SYSTEM ARE UNGROUNDED AND MAY BE ENERGIZED' (CEC 690.35(F)). Plus a permanent plaque or directory denoting all electric power sources on or in the premises (CEC 705.12). 78% · standard plan form (County-published)
• Does the authority specify placard wording of its own? Yes 78% · standard plan form
• Does it specify letter height, colour or material? Guidance rather than a hard specification. The Standard Plan's informational note reads: 'ANSI Z535.4 provides guidelines for the design of safety signs and labels for application to products. A phenolic plaque with contrasting colors between the text and background would meet the intent of the code for permanency. No type size is specified, but 20 point (3/8") should be considered the minimum.' 78% · standard plan form
• Is a site plan / facility map placard required, and what must it show? Yes. Two distinct requirements: (a) 'CEC 705.12 requires a permanent plaque or directory denoting all electric power sources on or in the premises'; (b) a submitted diagram of the roof layout showing all panels and modules, the clear access pathways, the approximate location of the electrical disconnecting means, and the roof access points. 80% · standard plan form + eligibility checklist
• Where must the labels be placed? At the inverter output connection overcurrent device; at the main service panel (dual power source plaque); at the PV system AC disconnect; at the PV system DC disconnect; on junction and combiner boxes and on conduit every 10 feet; at the inverter (ground-fault and ungrounded-conductor warnings). The permanent power-source directory goes on or in the premises per CEC 705.12. 78% · standard plan form

Where the AC disconnect must sit relative to the meter is usually the utility's rule, not the building department's. Battery storage frequently carries its own permit, its own inspection and its own fire conditions.

• Must equipment be on a specific approved list? No specific County approved list. Equipment must be listed and identified for the application: 'Listed and labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling (CEC 110.3). Equipment intended for use with PV system shall be identified and listed for the application (CEC 690.4[D]).' Modules must carry a UL-2703 fire rating, and manufacturer's specification sheets must be provided for the inverter, modules, combiner/junction boxes and racking. 75% · standard plan form + permit page
• Are batteries permitted, and under what conditions? Yes, permitted, with its own instant-approval path. Residential ESS up to 38.4 kW AC nameplate qualify for instant Symbium approval; commercial systems and residential ESS above 38.4 kW AC must go through the Accela online permit center. The application must state ESS manufacturer and model, size in kWh, total number of units, location (detached structure, attached garage, exterior wall, outdoors, closet, or utility space) and separation of ESS units; submittals are site plan, floor plan, single line electrical drawing with warning labels, warning placard, electrical wiring details, load calculations, mounting details and manufacturer specifications. IMPORTANT: the expedited SOLAR path excludes batteries — Eligibility Checklist item D requires the system be 'utility interactive and without battery storage'. 80% · permit page
• Is there a separate ESS permit or inspection? Yes — a separate Energy Storage System Permit with its own fee line: $536 for the first storage unit, $60 for each additional unit 88% · fee schedule + permit page
• Is a ground mount treated as a structure? Ground-mounted systems are excluded from instant approval and must be applied for through the Accela online permit center — i.e. full manual review rather than the expedited path 60% · permit page
• Is there a local rule on service upgrades or busbar sizing? No local amendment. The expedited path itself is bounded: interconnection must be to a single-phase 120/240 Vac service panel with a bus bar rating of 225 A or less; combined supply OCPD limits are set by Standard Plan Table 4 per CEC 705.12(D)(2) (e.g. 225 A bus with 200 A main allows 60 A max combined PV OCPD at the 120% rule, 25 A at 100%); and 'Reduction of the main breaker is not permitted with this plan'. 75% · standard plan form
• Is a specific mounting system or attachment spacing required? Yes — Structural Criteria Table 1 sets maximum horizontal anchor spacing by roof slope and rafter spacing. For PV arrays (4 psf max): flat to 6:12 gives 5'-4" at 16" o.c., 6'-0" at 24" o.c., 5'-4" at 32" o.c.; 7:12 to 12:12 gives 1'-4" / 2'-0" / 2'-8"; 13:12 to 24:12 the same. Staggered anchors may double the spacing but never exceed 6'-0". Manufactured plated wood trusses at flat to 6:12 are capped at 4'-0" with adjacent rows staggered. Fasteners: 5/16" diameter lag screws with 2.5" embedment into the rafter, or the manufacturer's guidelines. Array must be flush (modules parallel to roof plane), with a 2"-10" gap under the module, no overhang of ridges/hips/gable ends/eaves, no more than 4 psf, and covering no more than half the total roof area. 85% · published checklist

Booking is a portal, a phone call or an email depending on the authority, and the notice required is rarely zero. Book before the work is finished rather than after — the lead time, not the work, is usually what sets the date.

• How is an inspection booked? Portal (Accela Citizen Access) — with phone permitted at the Building Official's option 90% · department page + ordinance
• How much notice is required? At least one day 80% · adopting ordinance
• Are same-day or AM/PM windows offered? Yes — a 3-hour estimated time window, published online after 7:30 am on the inspection day. Inspections are scheduled between 8:00 am and 3:30 pm. 90% · department page

Some authorities inspect their own solar work; some delegate it, and a few do not inspect the PV equipment itself at all. Who is coming determines what they will look at.

• Does this AHJ perform its own final solar inspection? Yes 88% · department page + directory
• If delegated, to whom? Not delegated — the County inspects. (Fire review, where triggered, is a plan-check referral to the San Mateo County Fire Marshal's Office, not a delegation of building inspection.) 80% · department page

A rough-in or mid-roof inspection, where one is required, has to happen before the work it covers is closed up. Missing a stage means opening something back up, and it is the most expensive kind of correction.

• Which inspections are required, and in what order? Not published for solar specifically. The general rule is that inspection type and timing 'are dependent on the building permit type, but generally include initial inspections and a Final Inspection once all work under the permit is complete'. 55% · department page

The approved plan set, the permit, and the equipment listings should be on site and reachable. Inspectors routinely verify that installed equipment matches what was approved, and that the labels are the ones the plan set promised.

• Is there a published inspection checklist? No published inspection checklist for solar 60% · department page
• What must be on site at inspection? The permit card, posted at the work site; the approved plans, available to the inspector; the property address posted conspicuously and plainly visible in both directions from the street or road; and installation instructions for all equipment (expressly including bonding and grounding equipment). 85% · adopting ordinance + standard plan
• Does the inspector verify labels and listings? Yes 65% · standard plan form + eligibility checklist

Passing gives you a final or an equivalent sign-off. That is not the same as permission to operate: PTO comes from the utility, and who tells the utility the inspection passed varies. A system left switched off for weeks is usually waiting on this handover.

• What is issued on pass? Final (a final inspection sign-off, not a certificate of occupancy) 65% · department page
• Who notifies the utility for PTO? Installer — the contractor submits the interconnection paperwork to PG&E, and PG&E issues permission to operate after the city/county inspection 70% · utility page
• Is there a re-inspection fee? $197 80% · published fee schedule
• How are corrections issued and cleared? Where an inspection finds work incomplete or non-conforming, a re-inspection is required. A re-inspection fee may be assessed for, among other things, unauthorized deviation from the approved plans, requesting inspection before the work is complete, or failure to make corrections mandated at a previous inspection. Where re-inspection fees have been assessed, no further inspection is scheduled or performed until they are paid. At plan-check stage, comments from all reviewing agencies are consolidated and sent to the applicant as one set for correction and resubmittal. 70% · adopting ordinance + department page