DIY solar permit plans, from site plan to one-line diagram

Every building department and utility has its own list, but a residential solar plan set usually includes:

• Site plan. The property, the buildings, where the array goes, and where the inverter, disconnects, meter and main panel are.
• Roof or array layout. Module placement, rows and spacing, and roof setbacks or access pathways where the fire code requires them. For ground mounts, the array’s location and distances.
• Electrical plan. Equipment locations and the conductor runs between them.
• One-line diagram. How power flows from the modules to the point of interconnection, with ratings and conductor sizes.
• Labels. The warning labels and placards the electrical code requires, and where they go.
• Spec sheets. Data sheets for the modules, inverter or microinverters, racking, rapid shutdown equipment and any battery.
• Structural information. For roof mounts, attachment details and sometimes an engineer’s letter about the roof.

Ask your building department and your utility for their checklists before you start. The utility’s interconnection process is often separate from the building permit.

Solar plans are only as good as the equipment information on them. Attach the PDF data sheets for your modules, inverter, rapid shutdown devices and battery, and the assistant uses them as references while it draws and labels your equipment.

You can also attach a survey or plat for the site plan, roof photos, or an old plan of the house. AI CAD PRO accepts PDFs, images, ASCII DXF files, and text or CSV files. It can’t open DWG files, so export a PDF or an ASCII DXF from other software first.

Always check the ratings on your drawings against the spec sheets yourself. You’re the one who knows exactly which model you bought.

The one-line diagram is where solar plan reviewers spend their time. In AI CAD PRO, it’s built from the equipment you placed and the connections you explicitly defined. It doesn’t invent a utility service, meter, disconnect or battery connection you haven’t placed, so the diagram shows the system you plan to install, not a generic template.

If something is missing, you’ll know. Drafting checks flag missing electrical connection or specification data, and the Resolution center lists missing information with a recommendation and where to find it.

Not sure what belongs on the diagram? Our guide to the solar one-line diagram walks through every part, from strings to the busbar rule.

Describe where the array goes (“two rows of 10 modules on the south roof plane” or “a ground mount 60 feet south of the house”) and the assistant draws it on the site plan or roof plan. Add the equipment locations and the runs between them, and dimension what the reviewer will want to see.

Already have a site plan from another AI CAD PRO project? Ask the assistant to reuse that plot plan. See site plans for more on drawing the lot itself.

The same tools work for grid-tied systems, off-grid cabins and systems with battery storage. The paperwork differs. A grid-tied system usually needs the utility’s approval to interconnect as well as a building or electrical permit. Off-grid systems may skip the utility but still need permits in many places.

Print preview matches the PDF, and you can export a coordinated sheet set on Letter, Tabloid or Arch D paper for whichever office needs it.

AI CAD PRO is for drawing the plans. It doesn’t supply complete structural or electrical engineering calculations, so settle your system design and conductor sizes first and put the ratings from your spec sheets on the plans. Its drafting checks aren’t a code-compliance review. Some jurisdictions require an engineer’s letter or stamp for roof-mounted arrays, or a licensed electrician for parts of the work. Your permitting office and utility decide.