What inspectors check on a residential solar install

Passing inspection is not about luck — it is about matching the approved plans and the code the inspector is required to enforce. An inspector works from a checklist tied to the NEC, the IFC/IRC, and your submitted drawings. Knowing what they look for lets you build it right the first time.

Rough vs. final inspection

Some AHJs split solar into two visits. A rough inspection happens before anything is concealed — roof attachments, flashing, and any conduit that will be buried in a wall or attic. A final inspection covers the finished system: the modules, inverter, disconnects, labeling, and grounding.

Many residential jobs get one combined inspection instead. Either way, the concealed work has to be visible or documented when the inspector arrives, so plan the sequence with your permit set in hand.

Structural and mounting items

• Attachment spacing and type matching the structural plan (lag screws, standoffs, or hardware into rafters, not just sheathing)
• Flashing at each roof penetration for a weathertight seal
• Rail layout and cantilevers within the racking manufacturer's limits
• Rafter size and condition where the plan calls out an existing-framing check

Inspectors frequently probe attachments to confirm they hit framing. If your plan specifies a fastener and spacing, the field install must match it exactly.

Electrical items

• Conductor and OCPD sizing matching the one-line (wire gauge, breaker rating)
• Grounding and bonding — a grounding electrode, equipment grounding conductors, and array bonding per NEC 250 and 690.47
• Rapid shutdown device and initiator present and functional per NEC 690.12 (see our rapid shutdown explainer)
• Interconnection — busbar rating and back-fed breaker position, or a supply-side tap, matching the plan
• Working clearances around the service, disconnects, and inverter

Labels, placards, and disconnects

Labeling is one of the most cited final-inspection items. Inspectors look for the PV system disconnect marking, the rapid-shutdown placard, the directory/plaque at the service, and warning labels on junction boxes and conduit. A missing label is a quick fix but still a failed inspection and a return trip.

The AC and DC disconnects must be present, accessible, and labeled, with the utility-required lockable AC disconnect where the interconnection agreement calls for one.

Match the stamped plans

The single theme across every inspection is consistency: what is on the roof must equal what is on the approved drawings. If a field change was necessary — a different module, a relocated disconnect, a revised attachment pattern — document it and, when the change is significant, submit a revision before the inspection rather than surprising the inspector.

A design tool cannot guarantee approval, and a licensed electrician or PE must review and stamp the electrical and structural work. But a clean, code-accurate set that the installers actually follow is what turns an inspection into a formality. When you are ready to build the drawings, start with our DIY workflow or review the reference library for the code details behind each check.

Educational reference, reviewed 2026-07. A design aid, not a substitute for a licensed electrician or PE. Confirm the enforced NEC edition and local amendments with your AHJ.