City of Millbrae

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 92% · municipal code
• What does this authority permit itself, and what does it delegate? Both (in-house) for Building and Electrical; fire is delegated to Central County Fire Department 90% · municipal code
• Is a permit required for a residential rooftop PV system? Yes 95% · municipal code
• Is there a separate electrical permit, or is it combined? Combined 65% · permit application form
• Is a HOA or architectural approval required first? No — the City will not condition approval of an eligible small residential PV application on association (HOA) approval 85% · municipal code
• Is there a historic-district review? No — Millbrae's code contains no historic-district or landmark ordinance at all 78% · municipal code
• Is a wind or windstorm certification required? No stand-alone windstorm certification is required; wind exposure (Exposure B or C, with Special Wind Region conditions) is addressed as a prescriptive-eligibility factor inside the Structural Criteria worksheet itself, not as a separate certificate 65% · department handout
• Is a Specific Use Permit or Council approval ever required? Yes, conditionally — the Building Official may require a Use Permit if the system could have a 'specific, adverse impact' on public health/safety; that decision is appealable to the Planning Commission 90% · municipal code
• Is there a system-size cap on residential generation? 10 kW AC nameplate / 30 kW thermal — this is an eligibility GATE for the expedited/AB 2188 'small residential rooftop solar energy system' definition, not a hard ceiling on residential generation; larger systems are not barred, they simply do not qualify for the streamlined review path 88% · municipal code

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 owner-builder) 65% · department handout
• Must the contractor be registered with this authority before applying? Yes — a City of Millbrae business license is required for any contractor doing work in the city (not a separate building-department contractor registration) 75% · department page
• Is a homeowner permitted to self-install and self-permit? Yes 70% · department handout

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? Completed permit application; City standard PV plan set; the Eligibility Checklist for Expedited Solar PV Permitting (general/electrical/structural/fire-safety Y/N items); the Structural Criteria for Residential Flush-Mounted Solar Arrays worksheet (or a PE-stamped structural calc package if any item on it fails); a roof diagram showing panel/module layout, access pathways, disconnect locations and roof-access points 85% · department handout
• How many copies, and in what format? Electronic only — hard-copy applications are not accepted 90% · department page
• Is a site plan required, and what must it show? Yes — a roof plan/diagram is required showing panel and module array layout, clear access pathways, and the approximate locations of electrical disconnecting means and roof access points 85% · department handout
• Are string and conductor calculations required? Partially — the eligibility checklist requires confirming PV string counts per MPPT input, fuse ratings and combiner limits (Electrical Requirements A-D), which functions as a simplified string-configuration check for expedited-eligible systems; full engineered conductor/string calculations are implicitly required only for systems that fail the checklist and go to standard plan check 60% · department handout
• Is a structural PE stamp required, and at what threshold? Yes, conditionally — a PE/structural-engineer stamp is required only if any item on the City's Structural Criteria for Residential Flush-Mounted Solar Arrays worksheet is answered 'No'; if all items are 'Yes,' no additional calculations are required 90% · department handout

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? eProcess360 (millbrae.ca.eprocess360.com) 92% · department page
• Can the whole application be completed online? Yes 88% · department page
• What does a residential solar permit cost? $500 flat for residential PV systems 15 kW AC or less (includes plan review); +$15 per kW above 15 kW (plus plan review at the hourly rate). Battery Storage: $141.01 each. Residential Solar Thermal: $450 for 10 kWth or less. 92% · fee schedule
• How is the fee calculated? Tiered — flat fee up to a kW threshold, then per-kW above it 90% · fee schedule
• Is there a separate plan-check fee? No separate plan-check fee for residential PV ≤15 kW AC (plan review is included in the $500 flat fee); above 15 kW, plan review is billed separately at the hourly rate ($291.55/hr) 88% · 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? For expedited-eligible small residential PV: same day (over-the-counter) or 1-3 business days (electronic applications). For systems that fail the eligibility checklist: 5 working days, standard process. General (non-solar) building permits: allow 15 days for all plan-check activities. 85% · municipal code
• How long is an issued permit valid before it expires? 12 months from issuance (permit expires if work has not commenced within 12 months, or is suspended/abandoned for 12 months); up to one or more 180-day extensions may be granted by the Building Official for cause 88% · municipal code
• Which utility handles interconnection here? Pacific Gas and Electric Company (PG&E) 92% · municipal code (franchise ordinance)
• Where does the utility sit in the sequence? Parallel/after permit — PTO is gated on the City's final-inspection clearance 65% · utility tariff

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? 2023 NEC (adopted as part of the 2025 California Electrical Code) 92% · municipal code
• Which building code edition is in force? 2025 California Building Code and 2025 California Residential Code 92% · municipal code
• Which fire code edition is in force? 2025 California Fire Code (Title 24, Part 9) together with the International Fire Code, 2024 Edition, as amended by the State of California 92% · municipal code
• Are there local amendments to any of the above? Yes — extensive local amendments exist to the Fire, Electrical and Mechanical codes (MMC Chapter 9.10), plus a 2020 sustainable 'reach code' ordinance (Ord. 783) amending the Energy Code (9.50) and Green Building Code (9.35). Note: the current Title-24-cycle amendments were codified by Ord. 821 on 11/25/2025 — after AB 130's 1 Oct 2025 freeze on more-restrictive residential amendments began; whether any of these specific amendments affect one- and two-family residential construction in a way subject to AB 130 review, or were filed/accepted by BSC, could not be determined in this run and is left as an open question rather than asserted either way. 75% · municipal code
• What is the installation judged against? The 2025 California Electrical Code (based on the 2023 NEC), subject to the City's local amendments in MMC 9.10.410-425 (none of which are PV-specific) 85% · municipal code

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 Millbrae-specific ridge-setback distance or pathway width is codified. The Eligibility Checklist's Fire Safety Requirements only require confirming 'Clear access pathways provided' without stating dimensions, so the unamended 2025 CFC/CRC prescriptive pathway and ridge-setback provisions apply by default. 62% · municipal code

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? Yes, under the 2023 NEC §690.12 (via the 2025 CEC), applied unamended — Millbrae has not adopted its own local rapid-shutdown rule 62% · municipal code

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? No AHJ-specific placard content beyond the unamended state code's generic markings/labels requirement — Millbrae's own Eligibility Checklist only requires confirming 'All required markings and labels are provided' without naming any specific placard 70% · municipal code
• Does the authority specify placard wording of its own? No 78% · municipal code
• Does it specify letter height, colour or material? No 78% · municipal code
• Is a site plan / facility map placard required, and what must it show? Yes, functionally — the Eligibility Checklist requires 'a diagram of the roof layout of all panels, modules, clear access pathways and approximate locations of electrical disconnecting means and roof access points' as part of the submittal, serving the same purpose as a 705.10 facility/site plan placard, though it is a submitted drawing rather than a posted physical placard 78% · department handout

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? Yes 85% · municipal code
• Are batteries permitted, and under what conditions? Batteries are not addressed by a dedicated ordinance; they are excluded from the expedited/streamlined path. The Eligibility Checklist's General Requirements item E requires the system be 'utility interactive and without battery storage' to qualify for expedited review — a system with a battery must go through standard (non-expedited) plan check, for which no separate published battery/ESS conditions were found. 65% · department handout
• Is there a separate ESS permit or inspection? Likely yes, based on a distinct fee line, but no dedicated ESS ordinance or permit process is published 55% · fee schedule
• Is a ground mount treated as a structure? Yes, by inference — Millbrae's zoning code defines 'Structure' broadly as 'anything constructed or erected, the use of which requires location on or in the ground, or attachment to something having location on or in the ground,' with no PV-specific ground-mount carve-out or standard anywhere in Title 10 68% · municipal code
• Is there a local rule on service upgrades or busbar sizing? No Millbrae-specific busbar or service-upgrade ordinance was found. The '225A or less' single-phase busbar figure that appears in the solar Eligibility Checklist is the statewide AB 2188/CALSEIA expedited-permitting template's own eligibility threshold, not a locally codified Millbrae rule (Millbrae's Electrical Code amendments at 9.10.410-425 do not mention busbar sizing). 68% · department handout
• Is a specific mounting system or attachment spacing required? Yes — the City's own 'Structural Criteria for Residential Flush-Mounted Solar Arrays' worksheet prescribes: modules parallel to the roof plane with a 2"-10" gap to the roof surface, no overhang past roof edges, array covering no more than half the total roof area, and a Table-1 anchor horizontal-spacing standard tied to roof framing type/slope, with 5/16" lag screws at 2.5" rafter embedment (or manufacturer's guidelines) for wind-uplift resistance 90% · department handout

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? Phone 85% · department page
• How much notice is required? At least 1 business day (current department guidance); for eligible small residential PV specifically, MMC 9.15.060.H commits to scheduling within 2 business days of the request 82% · department page
• Are same-day or AM/PM windows offered? For eligible small residential PV: a 2-hour inspection window is offered, scheduled within 2 business days of the request. No general AM/PM-window system is described for ordinary building inspections beyond the (stale, 2005) FAQ's route-based afternoon schedule. 78% · municipal code

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% · municipal code
• If delegated, to whom? Fire only, conditionally, to Central County Fire Department; building/electrical are not delegated 88% · municipal code

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? For eligible small residential PV: a single consolidated City inspection (with a follow-up only if the installation fails to conform to the approved plans/Title 24), plus a possible separate CCFD fire inspection if required. Millbrae's general (non-solar) building-permit process runs five sequential inspection stages — Concrete/Underground, Below Floor, Above Floor, Coverings, Final — per the department's own (2005-dated) inspection FAQ, though a rooftop PV retrofit would typically only need the Final stage. 72% · municipal code
• Is a rough-in or mid-roof inspection required? No 85% · municipal code

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? Yes 90% · department handout
• What must be on site at inspection? The approved plans/permit card and permit number should be available; the inspector verifies the installation against the approved plans and Title 24 requirements 55% · municipal code
• Does the inspector verify labels and listings? Yes, by inference 65% · department handout

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 signed-off final inspection / approved permit) — not a new Certificate of Occupancy, which the City reserves for new structures or occupancy changes 65% · department page
• Who notifies the utility for PTO? Installer (applicant submits evidence of the AHJ's final inspection clearance to PG&E as part of the interconnection application) 55% · utility tariff
• Is there a re-inspection fee? $291.55 per hour, charged for reinspection without corrections made 88% · fee schedule
• How are corrections issued and cleared? Corrections are noted on the permit card/a written correction notice; the applicant corrects the work and calls to schedule a reinspection; the process repeats until the work passes. For solar specifically, MMC 9.15.060.H authorizes a follow-up inspection if the installation does not conform to approved plans or Title 24, to be done 'in a timely manner' with 'consolidated inspections.' 70% · municipal code