Key takeaways
- A permit-ready solar plan set is typically six sheets: cover, site plan, roof/array layout, structural details, single line diagram, and labeling/placards — plus manufacturer cut sheets.
- A plan set is not a proposal. A proposal sells the job to the homeowner. A plan set proves the job to the plan checker.
- The single line diagram is where most plan checks are won or lost, because it’s where conductor sizing, overcurrent protection, and the interconnection method all have to agree with each other.
- Every code citation on the sheet has to name the cycle your AHJ adopted — jurisdictions across the country are spread across multiple NEC editions, so the cycle has to be confirmed with the AHJ, not assumed.
- Avila Solar Drafting turns standard plan sets around in 2–3 business days, or 1–2 for Fast Roof.
What is a solar plan set?
A solar plan set is the drawing package an authority having jurisdiction (AHJ) reviews before issuing a building or electrical permit for a PV system. It documents where the array goes, how it attaches, how it’s wired, and which code sections the design satisfies. It is a construction and compliance document — not a sales tool, and not a production estimate.
Most residential solar plan sets run six sheets. Commercial packages run longer, and add structural calculations and equipment schedules. Below is what belongs on each sheet, and why a plan checker cares. For the fuller intake-to-AHJ workflow this sheet list supports, see residential solar design: intake to AHJ-ready plan set.
What’s included in a solar plan set?
A complete residential permit package contains six drawing sheets plus supporting documentation: a cover sheet, a site plan, a roof plan with array layout, structural attachment details, a single line diagram, and a labeling sheet. Manufacturer specification sheets for modules, inverters, racking, and any energy storage are submitted alongside them.
That structure isn’t arbitrary — it maps to what jurisdictions actually ask for. The City of San Diego’s Information Bulletin 301, a representative residential PV submittal checklist, requires a site plan showing panel, disconnect, inverter, battery, sub-panel and meter locations; a roof plan showing slopes, panel placement relative to ridges, hips and valleys, existing roof equipment and connection details; a single-line diagram covering panel specifications, voltage, disconnects, combiners, inverter ratings and conductor sizes; and manufacturer specifications for every major component.
Different AHJs order these differently and some fold two sheets into one. The content doesn’t change much. What changes is how strict the plan checker is about seeing it stated explicitly rather than implied.
The move toward standardized submittals is making this more uniform. The U.S. Department of Energy describes SolarAPP+ as giving developers “a streamlined form that includes all the required specifications for permit applications” — a single consistent format across every jurisdiction that adopts it. Where SolarAPP+ isn’t adopted, you’re still building to local expectations, and that’s where judging plan set quality becomes a real operational skill.
What does the site plan have to show?
The site plan establishes the property, the structure, and where every piece of equipment lands on it. At minimum: property lines with dimensions, the building footprint, north arrow and scale, the array outline, and the physical location of the inverter, disconnects, main service panel, meter, and any energy storage.
Two things get site plans rejected more than anything else.
The first is equipment location that doesn’t match reality. If the plan shows the AC disconnect on the south wall and the installer puts it on the east wall next to the meter, the inspector fails it — even though the east wall was the better call. The drawing is the contract.
The second is missing access and clearance dimensions. Working space in front of electrical equipment, the distance from the meter to the utility disconnect, and setbacks from property lines all have to be dimensioned on the sheet rather than left to the plan checker’s ruler.
We dimension all of it as a matter of course, because an undimensioned site plan is the cheapest possible correction to receive and the most annoying one to fix.
What goes on the single line diagram?
The single line diagram shows the complete electrical path from module to point of interconnection: string configuration, DC conductor sizing, inverter ratings, AC conductor sizing, every overcurrent protective device, disconnect locations, grounding and bonding, and the interconnection method. It is the sheet plan checkers spend the most time on.
The reason it draws scrutiny is that the SLD is the only sheet where every number has to reconcile with every other number. Conductor ampacity has to support the calculated continuous current. The OCPD has to protect the conductor. The interconnection has to satisfy the busbar rules. If any one of those three is off, all three read as wrong.
Interconnection is the usual failure point. Under NFPA’s NFPA 70, the National Electrical Code, the busbar sizing rules at NEC 2023 705.12(B)(2) — what installers call the 120% rule — cap what you can backfeed into an existing panel. Get it wrong and the fix isn’t a redline; it’s a different interconnection method and a redrawn sheet.
Rapid shutdown belongs here too. NEC 2023 690.12(B)(1) requires controlled conductors outside the array boundary to drop to 30 volts or less within 30 seconds of initiation, and 690.12(B)(2) sets an 80-volt limit inside the boundary on the same clock. Which cycle applies is a jurisdictional question, which is why our NEC solar and storage rules breakdown treats the adopted cycle as the first thing to establish, not the last.
What structural information does a solar permit need?
The structural sheet has to show the existing framing, the attachment method, and the load path. That means rafter or truss size and spacing, span, attachment spacing, the specific standoff or mount being used, fastener type and embedment, and dead, live, wind and snow loads for the site.
Wind and snow figures come from the ASCE 7 edition referenced by the IBC or IRC your jurisdiction has adopted — ASCE 7-16 and 7-22 produce different numbers for the same roof, so naming the edition matters.
When the existing framing won’t carry the load, or the jurisdiction requires it regardless, the package needs a stamped structural review from a licensed PE in that state. Plenty of AHJs require a stamp on every ground mount and on any roof-mount above a certain size or wind exposure. Some require none. Assume nothing and check the jurisdiction’s PE stamp requirements.
This is also where common solar design mistakes show up most expensively, because a structural correction usually means a site revisit rather than a drafting fix.
What’s the difference between a plan set and a proposal?
A proposal is a sales document showing estimated production, savings, and system cost to the customer. A plan set is a code-compliance document showing an AHJ how the system will be built. They serve different audiences and neither substitutes for the other.
Installers sometimes submit proposal output — a shade report, an Aurora or Helioscope layout — expecting it to serve as a permit drawing. It won’t. The production model has no conductor schedule, no OCPD ratings, no attachment detail, no code references.
That said, the two are connected. Accurate shade and production modeling feeds the array layout that ends up on the roof plan, so the numbers you sold and the numbers you build should trace back to the same site survey data.
Worked example: a 7.2 kW retrofit on a 200 A service
Say you’re adding 18 × 400 W modules to a home with a 200 A main service panel and a 200 A main breaker, using a 7.6 kW inverter.
Continuous AC output current is 7,600 W ÷ 240 V = 31.7 A. NEC 2023 690.8(B) requires the conductor and overcurrent device to be sized at 125% of continuous current: 31.7 × 1.25 = 39.6 A, so a 40 A backfeed breaker.
Now check the busbar. The 120% allowance on a 200 A busbar is 240 A. Your main breaker is 200 A. 200 + 40 = 240 A — exactly at the limit.
It fits. But there is zero headroom. If the customer later adds a battery, an EV charger, or a heat pump, that panel is done. A plan set that notes the calculation on the sheet tells the plan checker you did the math, and tells the installer why the panel is at capacity. One that just shows a 40 A breaker invites a correction asking you to prove it.
That calculation, stated explicitly, is the difference between a package ready to submit and one that generates a round trip.
What changes when the project is commercial?
A commercial package keeps the same core sheets and adds engineering deliverables: structural calculations with a ballast layout or a penetration schedule, a three-line diagram in place of the single line, an equipment schedule for switchgear and transformers, and a monitoring plan for the data acquisition system.
The roof is usually flat, which splits the attachment question two ways. Ballasted racking holds the array down with concrete blocks and adds distributed dead load the structure has to carry, so the structural sheet gains a ballast layout showing block count and placement by roof zone. Penetrating racking transfers load into the deck or purlins instead, and needs a penetration schedule: location, fastener and flashing detail at each one. Large flat roofs often end up hybrid — ballasted across the field, mechanically attached at the corner and perimeter zones where uplift is highest.
The electrical package changes shape too. Service is typically three-phase, so the diagram carries phase arrangement, line-to-line and line-to-neutral voltages and per-phase balancing rather than a single 240 V calculation. Larger sites interconnect at medium voltage, which brings switchgear, a step-up transformer, utility metering and protective relaying onto the sheet, each with a rating, a position on the one-line and a cut sheet.
Then there’s the data acquisition system. Commercial financing and incentive compliance depend on metered production data, so the DAS is a permitted part of the design rather than an accessory: revenue-grade metering, current transformers, the communications pathway and the low-voltage runs tying them together all belong on the drawings.
Our commercial solar PV designs carry those additions as standard. Settle the ballast-versus-penetration decision before the structural sheet is drawn, because changing it later redraws the roof plan too.
FAQ
What’s included in a solar plan set?
Six sheets for a typical residential project: cover sheet, site plan, roof plan with array layout, structural attachment details, single line diagram, and a labeling and placard sheet. Manufacturer specification sheets for modules, inverters, racking and storage are submitted with them. Commercial packages add equipment schedules and structural calculations.
How long does it take to get solar plan sets?
Avila Solar Drafting delivers standard plan sets in 2–3 business days, and Fast Roof plan sets in 1–2 business days when a Roof Order or EagleView XML file is supplied with the order. Turnaround starts when complete site data is received.
Do I need a PE stamp on my solar plans?
It depends on the jurisdiction and the project. Many AHJs require a licensed PE stamp on all ground mounts, on roof mounts above a size threshold, or in high wind and snow zones. Others accept unstamped plans for standard residential retrofits. Confirm with the AHJ before submitting.
What’s the difference between a plan set and a proposal?
A proposal estimates production and cost for the customer. A plan set documents code compliance for the AHJ. A proposal cannot be submitted for permit, and a plan set is not a sales document.
What does an AHJ look for in a solar permit submittal?
Consistency, mostly. Plan checkers verify that conductor sizing, overcurrent protection, and the interconnection method agree with each other and with the adopted code cycle; that equipment locations on the site plan match what will actually be installed; and that structural attachment details reference real framing dimensions.
What NEC code cycle does my jurisdiction use?
It varies by state and often by municipality, and jurisdictions across the U.S. are spread across multiple NEC editions. Confirm the adopted cycle with the AHJ before drafting, because rapid shutdown and interconnection language differ meaningfully between them.
Order your next plan set
Most installers don’t lose time on drafting. They lose it on the second submittal, three weeks after the first one.
Avila Solar Drafting builds permit-ready solar plan sets in 2–3 business days, backed by our guarantee of accurate solar plan sets and six months of free revisions from the order date — designed to pass first-time review.
Working on something commercial, utility-scale, or with an unusual structural condition? Call 971-410-0655 and we’ll scope it directly.
