A solar inspection checklist covers seven things: your approved paperwork, the roof mounting and flashing, fire-access pathways and setbacks, electrical wiring and grounding, rapid shutdown function, required labels, and battery storage placement if your system has it. The inspector compares each against the plans your building department already approved and against the National Electrical Code (NEC) and local fire code. Pass on the first visit and you move on to your utility for Permission to Operate; fail any item and you schedule a re-inspection.
Here is what each category involves and what the inspector actually looks at.
Documentation Ready at the Door
Inspectors start with paperwork, not with the roof. They want the approved site plan, a single-line wiring diagram showing how electricity flows from the panels through the inverter to the grid, and equipment specification sheets listing the exact panel wattage and inverter model installed. If the equipment on the roof doesn’t match what’s on paper, the visit effectively stops there.
Keep the permit card, approved plans, and equipment cut sheets in a weather-protected binder near the main electrical panel. If your installer provided torque verification logs or manufacturer installation checklists, add those too. Inspectors move faster when they can cross-reference documents against the physical work without hunting.
Roof Mounting, Flashing, and Rail Spacing
The racking anchors everything, so every attachment point gets scrutinized. Lag bolts must land in the center of rafters or trusses, not just the roof sheathing. A bolt that misses the rafter has almost no holding power, and the inspector will catch it from the attic or by checking the bolt pattern against known rafter spacing on the plans.
Every penetration needs proper flashing. The metal or rubberized flashing around each lag bolt must sit beneath the surrounding shingles or tiles so water sheds over it rather than pooling underneath. Cracked shingles, displaced tiles, or flashing that sits on top of the roofing material will fail. The weatherproofing materials also need to be compatible with the existing roof so the roofing warranty survives.
Racking rails must be spaced to the manufacturer’s engineering specifications. Inspectors verify that rail spacing matches the load tables in the approved plans, accounting for the weight of the panels plus local wind and snow loads. Fastener torque requirements vary by manufacturer and bracket type, which is why those torque verification records matter. Rail-to-roof connections that haven’t been torqued to spec are one of the easier structural items to fail on.
Fire-Access Pathways and Setbacks
This category has nothing to do with electricity and is one of the most commonly overlooked. Fire codes require clear pathways on the roof so firefighters can reach the ridge to ventilate a burning structure. If your panels cover too much of the roof with no clear walking paths, the inspection fails regardless of how clean the wiring looks.
The International Fire Code sets the dimensions most jurisdictions adopt, sometimes with local modifications:
- At least two 36-inch-wide pathways from the lowest roof edge to the ridge, on separate roof planes, with at least one facing the street or driveway side.
- Ridge setback of 18 inches on both sides if the array covers one-third or less of the roof area; 36 inches on both sides if it covers more than one-third.
- At least 18 inches of clearance from any hip or valley line where panels sit on both sides.
- At least 18 inches from the ridge for smoke ventilation, so firefighters can cut ventilation holes.
These dimensions come from IFC Section 1204.2 for residential buildings, and inspectors measure them on-site.1International Code Council. 2018 International Fire Code Chapter 12 – Energy Systems Your installer should have designed the layout to comply, but the inspector verifies it independently.
Wiring, Grounding, and Ground-Fault Protection
Wiring accounts for a huge share of inspection failures. One national quality study found wire management problems on 38 percent of residential solar projects, including low-hanging cables, improper splicing, and incorrectly installed connectors. Every run of conduit, every junction box, and every termination point gets looked at.
Conduit must be securely fastened at the intervals the NEC requires for the wiring method in use. Single-conductor PV wire in cable trays must be supported every 12 inches and secured every four and a half feet; jacketed multiconductor cable must be secured at least every six feet.2International Code Council. 2021 International Solar Energy Provisions – 690.31 Methods Permitted Loose cables draped across the roof surface invite abrasion, animal damage, and eventual short circuits. Wiring running through fire-rated walls or ceilings must be properly sealed with approved firestopping to maintain the assembly’s fire resistance rating.
Grounding is a high-priority item. NEC Article 690.47 requires every building supporting a PV system to use a grounding electrode system, and the modules, mounting rails, and inverter frames all need a continuous grounding path back to earth.3International Code Council. 2021 International Solar Energy Provisions – 690.47 Grounding Electrode System Inspectors test continuity across bonding connections and look for missing or disconnected grounding lugs, among the most common deficiencies in quality inspections.
DC circuits exceeding 30 volts or 8 amperes also need ground-fault protection capable of detecting faults and automatically disconnecting the affected circuit.4International Code Council. 2021 International Solar Energy Provisions – 690.41 System Grounding The ground-fault protection equipment must provide a visible fault indicator at an accessible location, which the inspector will confirm is both present and reachable.
Interconnection and the 120% Rule
Where the system ties into your main panel, inspectors check overcurrent protection and whether the panel’s busbar can carry the combined load. NEC Section 705.12 sets the math: 125 percent of the solar system’s output current plus the main breaker rating cannot exceed 120 percent of the busbar’s ampere rating. The solar breaker must sit at the opposite end of the busbar from the main breaker. A permanent warning label reading “Warning: Power source output connection — do not relocate this overcurrent device” must be affixed next to the solar breaker. If the math doesn’t work with your existing panel, the installer may need to derate the main breaker or upgrade the panel.
Rapid Shutdown Function
Rapid shutdown exists to protect firefighters, who need to de-energize rooftop solar before cutting into a burning roof. NEC Section 690.12 requires controlled conductors outside the array boundary to drop to no more than 30 volts within 30 seconds of initiation, and conductors inside the array boundary to drop to no more than 80 volts in the same window.
The inspector verifies that the initiation device is installed, labeled, and functional. A clearly marked switch must be present, and activating it must actually bring voltage down within the required time. Module-level power electronics such as microinverters or DC optimizers are the most common way to meet the interior-boundary requirement, because they can shut down each panel individually.
Labels and Signage
Labeling looks minor until it fails your inspection. Required labels sit at the main service disconnect, the inverter, and along any conduit carrying DC current, and they warn firefighters, utility workers, and future electricians about energized components they might not expect.
The rapid shutdown label under NEC Section 690.56(C) is specific. The text “SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN” must appear in capitalized letters at least 3/8 inch tall. For systems that fully shut down both the array and all conductors, the title is black text on a yellow background. Systems that only shut down conductors leaving the array, while the array itself stays energized in sunlight, use white text on a red background and must include additional warning language about conductors remaining energized. Both types require an accompanying roof diagram showing which areas remain energized after shutdown.
Beyond rapid shutdown, NEC Section 705.10 requires a permanent plaque or directory at each service equipment location listing every power source disconnect on the property. The sign must include the marking “CAUTION: MULTIPLE SOURCES OF POWER” and any diagrams must be accurately oriented to their physical locations.5UpCodes. Identification of Power Sources Labels must be weather-resistant and durable enough to last the life of the system. Missing, illegible, or incorrectly worded signs fail the inspection.
Battery Storage, If You Have It
Systems with battery storage carry additional requirements from NFPA 855 and NEC Article 706. NFPA 855 caps individual residential battery units at 20 kWh of stored energy each. Units must sit at least three feet from doors, windows, and other openings, and must be separated from each other by at least three feet unless the manufacturer’s large-scale fire testing supports a smaller gap approved by the local authority. Total capacity limits depend on location: up to 40 kWh inside living or utility spaces, and up to 80 kWh in a garage, detached structure, or outdoor installation on an exterior wall.
The battery disconnect switch must be readily accessible without tools. Under NEC 706.15(B), it must either sit within the battery enclosure, within 10 feet and in direct line of sight of the system, or be equipped with a code-compliant locking mechanism that holds it off. Temporary lockout-tagout setups do not satisfy the requirement. Inspectors check both location and operability; a disconnect buried behind storage boxes in a garage won’t pass.
Where Inspections Most Often Fail
If you want to focus your pre-inspection walk-through, these are the issues flagged most often:
- Wire management: loose or sagging cables, improper splicing, and connectors that aren’t fully seated. This single category drives deficiencies on roughly four out of ten projects nationwide.
- Labeling: faded, illegible, or missing labels; incorrect voltage values; missing rapid shutdown label or power source directory.
- Grounding: disconnected grounding conductors, missing bonding lugs on rails or modules, or an incomplete path to the grounding electrode.
- Plan-to-field mismatches: equipment installed in a different location or orientation than the approved plans show, or a different inverter model than specified.
- Fire setback violations: panels placed too close to the ridge, hips, valleys, or roof edges, blocking required access pathways.
Each correction is usually straightforward, but each one means scheduling a re-inspection. Re-inspection fees are generally modest; the real cost is the week or more the building department’s backlog can add to your project.
Preparing the House for the Visit
The inspector needs physical access to more than the roof. Expect them to enter the garage to examine the inverter and subpanel, enter the attic to verify that lag bolts hit rafters and to inspect any conduit runs there, and reach the main electrical panel to check interconnection, labeling, and breaker placement. Clear a path to each of these before they arrive. Post the permit card where it’s visible and keep the approved plan set and equipment spec sheets at hand.
Permission to Operate Comes After Passing
Passing the inspection is not the same as being allowed to generate power. After the local government signs off, you submit the approved inspection documentation to your utility, which reviews the results and processes your interconnection application. Once the utility verifies everything and installs or reprograms your meter, they issue Permission to Operate.6National Association of Home Builders. Solar Interconnection Process Only then can you legally energize the system and export power to the grid. Turning on the system before PTO can prompt the utility to disconnect your service, so the last stretch is worth waiting out.