Solar Permit Pre-Submittal Checklist for Installers

Run ten checks before a solar permit package leaves your office: site plan completeness, equipment listings and spec sheets, one-line and three-line agreement, conductor and OCPD sizing shown on the drawing, rapid shutdown labelling, structural load path, fire-code pathways and setbacks, interconnection application alignment, stamp requirements, and document-set formatting. Nearly all of them appear verbatim on published AHJ submittal checklists.

Key takeaways

• A pre-submittal gate is a fixed pass over a finished set, run by someone who did not draw it. It is a checklist, not a second opinion.
• Plan reviewers work from published checklists. Boulder County’s B46 solar checklist and the Washington MyBuildingPermit residential solar tip sheet both enumerate exactly what has to be on the sheets – read them as the answer key.
• Calculations have to be shown, not just done. Conductor sizes, insulation type, conduit sizes, OCPD ratings and busbar ratings all belong on the one-line.
• Name the code cycle on the cover sheet. Jurisdictions are spread across several NEC editions, and a set drawn to the wrong one is a correction before anyone reads page two.
• The plan set and the utility interconnection application have to describe the same system. Different inverter counts, different AC output, or a disconnect drawn in the wrong place will stall one or the other.
• Half of what gets a package bounced is not engineering at all – it is scale, sheet numbering, an unreadable PDF, or an address that does not match the application.

What does a pre-submittal QA gate actually check?

A pre-submittal QA gate is a fixed, written pass over a finished permit package, run by someone who did not draw it, immediately before submittal. It checks completeness and internal consistency rather than design intent: does every sheet exist, does every number agree with every other number, and is every claim on the drawing backed by a document in the same package.

The distinction matters. Design review asks whether the system is right. The gate asks whether the solar plan sets you are about to submit can be reviewed at all without a phone call. Those are different jobs, and the second one is the one that gets skipped when a crew is waiting on a permit.

Ten gates, in the order a plan reviewer tends to hit them:

1. Site plan completeness
2. Equipment spec sheets and listings
3. One-line and three-line diagram agreement
4. Conductor and OCPD sizing shown on the drawing
5. Rapid shutdown equipment and labelling
6. Structural attachment and load path
7. Fire-code setbacks and pathways
8. Utility interconnection application alignment
9. Stamp requirements
10. Document-set formatting

If you want the upstream version of this – what belongs in the package in the first place, rather than what to verify at the end – start with what a permit-ready plan set contains.

Is the site plan complete enough for plan review?

A site plan is complete when a reviewer can locate every piece of outdoor equipment, measure every required clearance, and confirm the array fits the roof – without asking you anything. Boulder County’s solar photovoltaic checklist requires disconnect locations, array layout with access and pathways, battery and inverter locations, grounding electrode conductor connections, equipment clearances, and dimensions to structures and property lines.

Check each of these before submittal:

• North arrow, graphic scale, and a stated sheet scale that matches the plotted geometry.
• Property lines with dimensions, and dimensioned setbacks from equipment to structures and lot lines.
• Every disconnect, inverter, combiner, battery enclosure and meter located and labelled – not just noted.
• Grounding electrode conductor route and connection point shown.
• Roof planes identified with azimuth, pitch and dimensions; array outline dimensioned to roof edges and ridges.
• Obstructions drawn: vent stacks, skylights, mechanical units, and any emergency escape and rescue openings the array must clear.
• Working clearances at every piece of electrical equipment, dimensioned.

Most site plan corrections are not drafting errors. They are survey errors that survived into the drawing – a vent stack nobody photographed, a main service panel that turned out to be on the other gable. A disciplined site survey checklist catches those for a fraction of what a resubmittal costs.

Are the equipment spec sheets and listings in the package?

Every major component needs a manufacturer datasheet in the package and a listing the reviewer can confirm. The MyBuildingPermit residential solar tip sheet used across Washington jurisdictions calls for modules listed to UL 1703 or to both UL 61730-1 and UL 61730-2, inverters listed to UL 1741, and mounting systems certified to UL 2703 with the manufacturer installation instructions included.

Boulder County goes further and names the specific values that have to be legible on the product listing sheets: module short-circuit current and open-circuit voltage, module series fuse rating, inverter output circuit current rating and UL listings, the module grounding method, and projected annual kWh output.

The gate here is three questions per component:

• Is the datasheet in the file? A model number on the one-line with no attached spec sheet is a correction.
• Is it the right revision? Manufacturers change Isc, Voc and temperature coefficients between module revisions. If the datasheet in the package does not carry the numbers used in the string calculation, the calculation cannot be checked.
• Is it on the approved list? Utilities and some AHJs maintain their own approved-equipment lists. Equipment that is UL listed but not on the utility’s list will still hold up interconnection.

Rack and flashing hardware gets skipped more than anything else in this section. UL 2703 covers module mounting, grounding and bonding as a system; the installation instructions are what tell the reviewer the rail spans and clamp zones in your structural calculation are legitimate. Judging a vendor on whether they include this by default is one of the fastest ways to assess plan set quality.

Do the one-line and three-line diagrams agree with the equipment?

The one-line is the sheet a reviewer reads hardest, and it fails on internal contradiction more than on omission. Boulder County requires the diagram to state system type (stand-alone, grid-tied or hybrid), conductor sizes, insulation types and materials, conduit sizes and materials, overcurrent device ratings, panel amperage ratings, and the series and parallel module configuration.

Run the diagram against the rest of the set line by line:

• Module count on the one-line equals module count on the roof plan equals module count in the structural calculation.
• Strings per MPPT and modules per string match the datasheet values used for string sizing at the site’s record low temperature.
• Inverter model, quantity and AC output current match the spec sheet and the interconnection application.
• Every disconnect on the one-line appears on the site plan in the same location.
• Existing service data is real: busbar rating, main breaker rating, service conductor size, meter form.

Three-line diagrams are a separate gate, and they show up on commercial work more than residential. Where the service is three-phase, where CT metering is involved, or where the AHJ wants phase-by-phase conductor and protection detail, a one-line will not carry enough information. Scope that early on commercial solar PV designs rather than discovering it in a correction letter – the three-line also has to show instrument transformer ratios, relay or protection settings where required, and phase identification consistent with the utility’s service.

Is conductor and OCPD sizing shown on the drawing, not just done?

A reviewer cannot approve arithmetic they cannot see. Conductor ampacity, the correction and adjustment factors applied, the resulting size and insulation type, the conduit fill basis, and every overcurrent device rating must appear on the sheets. So must the maximum system voltage calculation and the busbar interconnection calculation, with the code cycle named.

What to verify is on the drawing:

• Maximum PV system voltage per NEC 2023 690.7, calculated at the lowest expected ambient temperature for the site, with the temperature and the source of it stated.
• Circuit current and conductor ampacity per NEC 2023 690.8, with the 125 percent continuous-current factor, the ambient temperature correction, and the conduit-fill adjustment each shown separately rather than folded into one number.
• Overcurrent protection per NEC 2023 690.9, including module series fuse rating as the ceiling on string fusing.
• Equipment grounding conductor sized and shown for every circuit, not implied.
• Voltage drop where the AHJ or the utility asks for it, with the run length used.

The busbar check is the one worth writing out in full on the sheet. NYSERDA’s Solar PV – Permitting and Inspecting guide states the load-side allowance plainly for the 2017 NEC at 705.12(B)(3)(b): the sum of 125 percent of the inverter output current plus the main circuit breaker rating must be less than or equal to 120 percent of the busbar rating. The same allowance sits at NEC 2023 705.12(B)(3)(2). Note which factor does which job – 125 percent applies to continuous inverter output current, 120 percent is the busbar allowance. Mixing them is a correction, and it is a common one. For the wider article map, see which NEC articles govern a plan set.

Is rapid shutdown drawn, specified and labelled?

Rapid shutdown fails plan review in three places: the equipment that provides it is not identified, the initiation device is not located on the site plan, or the labels are not drawn with their text and mounting location. All three belong on the sheets, tied to the NEC cycle the jurisdiction has adopted rather than to the current published edition.

NEC 2023 690.12 sets the rapid shutdown requirement for PV systems on buildings, and Minnesota’s Department of Labor and Industry notes in its solar PV guidance that it applies to new systems rather than retroactively to existing ones – useful when a retrofit or module swap lands on an older array. Enphase’s technical brief covering NEC 2017, 2020 and 2023 compliance points to two items the drawing has to carry: PV system power source labelling under NEC 2023 690.56(C), and a PV system disconnect location that satisfies NEC 2023 690.13(A)(1).

Label content and construction are also reviewable. NYSERDA’s permitting guide gives the physical specification under the 2017 NEC: labels permanently affixed, suitable for the environment, with a minimum character height of 3/8 inch, white on a red background for DC circuits per NEC 2017 690.31(G)(4), which the 2020 and 2023 cycles carry at NEC 2023 690.31(D)(2). It also gives the two strings reviewers look for verbatim – “PHOTOVOLTAIC SYSTEM EQUIPPED WITH RAPID SHUTDOWN” and a disconnecting means marked “PV SYSTEM DISCONNECT” or equivalent, with open and closed position indicated. Label wording is cycle-specific, so check the exact text against the NEC edition your AHJ has adopted before you print the schedule.

The gate: a label schedule sheet listing every label, its exact text, its material, and its mounting location, cross-referenced to a callout on the site plan. If the label schedule is a single generic note, expect a correction.

Does the structural attachment show a complete load path?

A structural sheet passes when a reviewer can trace load from the module, through the clamp and rail, into the attachment, into a named framing member, and down to the foundation – with numbers at each step. Boulder County requires an engineer evaluation of dead-load capacity, wind and snow loads, and the roof penetration repair method for roof-mounted arrays.

The Washington MyBuildingPermit tip sheet, written to the 2021 International Residential Code Section R324, is unusually specific about what has to be verified, and it makes a clean checklist:

• Wind speed design calculation consistent with the racking manufacturer’s specifications.
• Ground snow load documented for the site.
• Dead load of modules, supports, mountings and raceways.
• Point load analysis, with that jurisdiction capping support point load at 50 pounds.
• Panel height confirmed at no more than 18 inches above the roofing surface.

Add the items the drawing itself has to show: existing framing member size, species and spacing taken from the survey rather than assumed; attachment spacing and rail span within the manufacturer’s published table; the specific attachment product and its fastener schedule; and the flashing detail. Where the roof cannot take the load as built, the reinforcement detail belongs in the same package – an engineering stamp on a sheet that does not show the reinforcement solves nothing.

Do the setbacks and pathways meet the adopted fire code?

Fire access is dimensional, and it is checked with a scale. Boulder County reviews solar submittals against the 2021 International Fire Code Section 1205 for access and pathways. The Washington tip sheet reduces the residential case to two numbers: roof access pathways at least 36 inches wide, and ridge setback clearances of 18 or 36 inches depending on how much of the roof the array covers.

Draw them, dimension them, and state the code edition you drew them to. What the gate looks for:

• Pathways shown as hatched or shaded zones on the roof plan with a leader and a dimension, not described in a note.
• Ridge setback dimensioned on both sides where the code requires it, with the array coverage percentage calculated and stated so the reviewer can see which threshold applies.
• Array clearance to vent pipes, mechanical equipment and emergency escape and rescue openings.
• The adopted fire code edition named on the cover sheet, because local amendments to setbacks are extremely common.

Amendments are the trap here. A jurisdiction can adopt the model code and then rewrite the setback table, or exempt a category of roof, or add a requirement the model code never had. Assuming the model text is what gets enforced is one of several permitting requirements that catch installers out.

Does the plan set match the utility interconnection application?

Building permit and interconnection are two reviews of one system, and they fail when the two descriptions drift apart. Portland General Electric, for example, requires UL 1741 tested and compliant inverters, documentation of any non-default inverter settings submitted with the application, and a lockable AC disconnect within 10 feet of the interconnection meter unless PGE has approved another location.

PGE also sets a drawing threshold: secondary services over 320 A single-phase or 200 A three-phase require a drawing package for utility review, including site plans and electrical diagrams, and its work is governed by Oregon Administrative Rules 860-082 for small generators and 860-039 for net metering, alongside PGE’s Electric Service Requirements. Primary voltage interconnections need lockable switching equipment with a visible break.

Every utility differs, so the gate is a comparison rather than a fixed rule. Put the application and the plan set side by side and confirm:

• DC nameplate and AC output rating are identical in both documents.
• Inverter make, model and quantity match, including any grid-support settings you declared.
• The utility-required disconnect is drawn where the utility requires it, with its lockable and visible-break characteristics called out.
• Service address, account number and meter number match the utility’s records, not the customer’s paperwork.
• Interconnection method – load side or supply side – is the same in both, and the busbar calculation supports it.

In California the equivalent framework is the CPUC’s interconnection tariff, and the plan set has to carry what it asks for; we cover that separately in Rule 21 for solar.

Does this project need a PE or SE stamp?

Settle the stamp question before the package is assembled, not after the first correction. There is no single national threshold. NYSERDA’s permitting guide, for instance, lists a site plan stamped by a professional engineer or registered architect among the required plan documents, while Boulder County calls for an engineer evaluation of the roof structure. Two jurisdictions, two different triggers.

What to confirm before you submit:

• Which discipline the AHJ wants stamped – structural, electrical, or both.
• Whether the engineer must be licensed in the project state, and whether the seal has to be wet, digital, or either.
• Which sheets carry the seal, and whether the AHJ wants the seal on every sheet or only on the engineered ones.
• Whether a signed calculation package has to accompany the sealed sheets.
• Whether a post-installation affidavit will be required at inspection, which is easier to arrange now than later.

Getting this wrong in either direction costs money – an unnecessary stamp is a fee you did not need, and a missing one is a resubmittal. We work through the triggers in detail in when a solar project needs a PE stamp.

What document-set formatting gets packages bounced?

A technically correct package still gets returned if the file is unusable. Formatting rejections are cheap to prevent and expensive to absorb, because they cost the same queue time as a real code correction while telling you nothing you did not already know.

The formatting gate:

• Sheet index matches the sheets. Every sheet listed exists; every sheet in the file is listed; numbering is continuous.
• Correct code editions on the cover. Electrical, building, residential and fire code editions as adopted by that jurisdiction, with the year on each.
• Legible at the sheet size the AHJ accepts. If they review at 11×17, check text height at 11×17.
• One flattened PDF unless separate files are requested, with searchable text rather than a scan, and no layers, comments or markup left in.
• Page orientation and size consistent across the set, with no rotated sheets.
• Address, parcel number and owner name identical on the cover sheet, the application and the utility paperwork.
• Revisions clouded and deltas dated on a resubmittal, with a response letter answering each comment by number.
• File naming that follows the portal’s convention, which several e-permitting systems enforce automatically.

None of this is engineering, and all of it is queue time. If you want the failure modes ranked, we catalogue them in why solar permits get rejected, and the surrounding workflow in the solar permitting process.

What does the gate look like on a real package?

A 7.6 kW residential retrofit: 20 modules at 380 W, one 7.6 kW string inverter, load-side breaker connection to a 200 A panel with a 200 A main. The gate takes about twenty minutes and turns on four numbers.

Busbar. Inverter continuous output current at 240 V is 31.7 A. Applying the 125 percent continuous factor gives 39.6 A, protected by a 40 A breaker. The busbar allowance is 200 A x 120 percent = 240 A. Main breaker 200 A plus 39.6 A of inverter current equals 239.6 A, which sits inside 240 A – so the load-side connection stands under NEC 2023 705.12(B)(3)(2). Drop the same array onto a 175 A panel with a 175 A main and it fails: the allowance is 175 A x 120 percent = 210 A, and 175 A plus 39.6 A is 214.6 A. When the sum does not fit, the options are a supply-side connection under NEC 2023 705.11, a line-side tap ahead of the service disconnect, a busbar upgrade or a derated main breaker, or a smaller PV output. Write the calculation on the sheet either way.

Voltage. The maximum system voltage under NEC 2023 690.7 is calculated at the site’s lowest expected ambient temperature, and the temperature source is stated on the sheet. If the module datasheet in the package is a different revision from the one the string calculation used, the number cannot be verified and the whole electrical review stalls.

Structure. Twenty modules across two roof planes, attachment spacing inside the racking manufacturer’s published rail span table, framing member size and spacing taken from the survey photographs rather than assumed, and the flashing detail on the sheet.

Fire access. Array coverage calculated as a percentage of total roof area and stated, so the reviewer can see which ridge setback threshold applies, with the 36 inch pathways hatched and dimensioned. Four numbers, twenty minutes, and a package a reviewer can clear in one pass. That discipline is a subset of the wider set of solar project design considerations worth settling before anyone opens AutoCAD.

Hand the gate to someone else

The reason pre-submittal QA gets skipped is that the person best placed to run it is the person who drew the set, and they cannot see it any more. Avila Solar Drafting produces permit-ready PV plan sets in 2-3 business days, or 1-2 business days on Fast Roof, drawn to the code cycle the jurisdiction has actually adopted and designed to pass first-time review. Revisions are free for six months from the order.

Order a plan set through the client portal, or call 971-410-0655 if the project needs scoping first.

Frequently asked questions

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Sources

• Boulder County, Solar Photovoltaic Systems Checklist (B46) – reviewed against the 2023 NEC and 2021 IFC Section 1205.
• MyBuildingPermit, Residential Solar Systems tip sheet – 2021 IRC Section R324, UL 1703 / UL 61730, UL 1741 and UL 2703 listing requirements.
• NYSERDA, Solar PV Permitting and Inspecting – load-side busbar arithmetic and label specifications under the 2017 NEC.
• Portland General Electric, Interconnection Equipment, Metering and Technical Requirements.
• Enphase, NEC 2017, 2020 and 2023 system code compliance technical brief.
• Minnesota Department of Labor and Industry, Solar photovoltaic and energy storage systems FAQ.