Solar Permit Plans for Residential and Commercial PV
PV site plans, electrical diagrams, string calculations and code labels prepared to the NEC for building permit approval and utility interconnection.
- Stamped by a PE licensed in your state
- Built to IBC, IRC and local amendments
- Plan-check comments answered
A complete PV plan set for the permit and the utility
Solar permit plans have to satisfy two reviewers: the building department, which checks the electrical design, fire access and roof structure, and the utility, which checks how the system connects to the grid. A plan set that leaves out string calculations, rapid shutdown details or the required labels is one of the most common reasons solar permits come back with corrections.
PE Engineer prepares PV plan sets for residential rooftop systems, ground mounts, solar carports, commercial rooftops and battery storage additions. The electrical design follows NEC Article 690 for PV systems and Article 705 for interconnected power production sources, as adopted by your jurisdiction, and plans are sealed by a Professional Engineer licensed in the state where the project is located whenever a seal is required.
When the roof or racking needs engineering, we provide a solar structural letter with the electrical set, so the building department receives both in one submittal and you are not coordinating two consultants on one small project.
What you receive
- Site plan with array layout and fire setbacks
- Single-line or three-line electrical diagram
- String sizing and conductor calculations
- Interconnection and busbar calculations
- Rapid shutdown and labeling details
- Equipment data sheets and stamped set
PV design services
We work for installers, homeowners and developers, and we format each set for the jurisdiction and utility involved.
Residential rooftop PV
Plan sets for microinverter, string inverter and optimizer systems on homes, with roof layout, fire access pathways and equipment locations at the meter and main service panel.
Commercial and ground-mount PV
Rooftop, ground-mount and carport arrays for businesses, farms and multifamily properties, with combiners, inverters, transformers and switchgear laid out where the project needs them.
String sizing and conductors
Maximum system voltage corrected for the record low temperature at your site, string lengths within inverter limits, and conductor ampacity, conduit fill and voltage drop calculations.
Interconnection design
Load-side or supply-side connection analysis, busbar and main breaker checks, and main breaker derate or panel upgrade options when the existing panel cannot accept the solar breaker.
Rapid shutdown and labels
The module-level or array-level rapid shutdown method shown on the plans, the initiator location, and the placards and warning labels required by the NEC and the fire code.
Battery energy storage
Battery and hybrid inverter additions designed to NEC Article 706 and NFPA 855, with backup load panel layout, installation location, clearances and the protection the fire code requires.
Your Stamped, Permit-Ready Plans Start With One Upload
Send your drawings or describe the project. A licensed engineer reviews it and sends a clear, fixed-fee proposal, often within hours.
- Free and no obligation
- Reviewed by a licensed PE
- Secure file upload
What goes into solar permit plans
A complete PV plan set gives the plan reviewer, the inspector and the utility everything they need without a follow-up call. Our sets typically include:
- Cover sheet with system size, equipment list, code references and the scope of work.
- Site plan showing the array, roof planes, fire access pathways and setbacks, and the location of the meter, main panel, inverters, disconnects and batteries.
- Array layout with module placement, attachment spacing and string assignments.
- Single-line or three-line diagram showing every module string, inverter, combiner, disconnect, overcurrent device and the point of interconnection, with conductor and conduit sizes.
- Calculations for string voltage, conductor ampacity, overcurrent protection, voltage drop and busbar capacity.
- Labels and placards with wording and locations as required by the NEC and the fire code.
- Equipment data sheets for the modules, inverters, racking and rapid shutdown devices.
Some jurisdictions use standardized or online permitting for simple residential systems, while others expect a full engineered set. We format the plans to match what your building department and utility ask for, and we keep the equipment data consistent across every sheet, because a module model number that differs between the cover sheet and the diagram is enough to trigger a correction.
String sizing, conductors and rapid shutdown
PV module voltage rises as temperature falls, so the coldest morning of the year sets the highest system voltage. We calculate the maximum string voltage from the module’s open-circuit voltage and temperature coefficient using the extreme minimum design temperature for your location, and we confirm that it stays within the inverter’s rating and the voltage limit the NEC sets for the building type. We also check that the string’s operating voltage stays inside the inverter’s tracking range on hot days.
Conductors are sized for the continuous current of the PV source and output circuits, with adjustments for conduit fill and for the high temperatures found on rooftops and in direct sunlight. Overcurrent protection is coordinated with the module ratings and the inverter’s input and output limits.
Rapid shutdown is required for PV systems on buildings. It limits the voltage on conductors inside and outside the array boundary within a set time after the initiator is operated, protecting firefighters who may need to work on the roof. Module-level power electronics, such as microinverters and optimizers, are the most common way to comply. Our plans identify the rapid shutdown method, show the initiator at a readily accessible location and include the required label, so the inspector can verify it at a glance.
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- Free and no obligation
- Reviewed by a licensed PE
- Secure file upload
Interconnection, busbar ratings and service upgrades
The point of interconnection is where most residential solar designs hit a limit. For a load-side connection through a breaker in the main panel, the NEC limits the combined current of the main breaker and the solar breaker relative to the panel’s busbar rating. The most common version of this check is often called the 120 percent rule, and it requires the solar breaker to be placed at the opposite end of the busbar from the main.
When a panel fails that check, there are several options:
- Derate the main breaker, if the calculated load of the building allows it.
- Make a supply-side connection ahead of the main breaker, where the equipment and utility permit it.
- Upgrade the main panel or busbar to a higher rating.
- Reduce the inverter output, or apply another busbar option the NEC permits.
We evaluate those options with a load calculation and coordinate the result with our electrical plans service when a panel upgrade or new service is needed. We also prepare the single-line diagram and system information that utilities request with an interconnection application, and we note any utility requirements, such as a visible lockable AC disconnect or production meter, that must appear on the plans.
Roof structure, fire access and battery storage
Solar adds weight to the roof and wind uplift on every attachment. Many building departments require a structural letter or calculations confirming that the existing roof framing can carry the array and that the racking is attached at an appropriate spacing. We provide that analysis from photos and framing measurements, and when a ground-mount or carport structure is involved, we design it through our carport and canopy engineering. Ground-mount arrays also need foundations, typically driven posts, helical piles or concrete piers, sized for the wind and snow loads at your site.
Fire codes require access pathways and setbacks on residential and commercial roofs so firefighters can move safely and ventilate the building. The required widths and locations depend on the roof layout, the code your jurisdiction has adopted and whether the building has sprinklers. We lay out the array to meet those rules from the start, rather than losing modules during plan review.
Battery energy storage systems add another layer of requirements. We design to NEC Article 706 and NFPA 855, show the installation location, clearances and protection the fire code requires, and lay out the backup load panel and transfer equipment.
To start, send the site address, photos of the roof, main panel label and meter, a recent utility bill, the proposed module and inverter models, and roof framing size and spacing if you have them. Most residential solar plan sets are delivered within a few business days of receiving complete information.
You likely need this if
- You are installing rooftop or ground-mount solar
- You are adding batteries to an existing system
- Your main panel cannot accept a solar breaker
- Your utility requires a single-line diagram
- You are building a commercial or carport array
- The city flagged rapid shutdown or labels
How it works, start to finish
From your first message to stamped drawings, you work directly with the engineering team.
- 1Share your projectSend the address, scope and any drawings, photos or plan-check comments. Two minutes is enough.
- 2Receive a fixed-fee proposalAn engineer reviews the scope and replies with a firm price and delivery date for your solar pv plans drawings.
- 3Engineering and draftingWe run the calculations and prepare drawings to the codes your jurisdiction enforces, checked before sealing.
- 4Stamped set deliveredYou receive a sealed PDF set ready to submit, and we answer any plan-check comments within scope.
Codes and standards we design to
PV and storage designs follow the editions adopted by your jurisdiction, along with your utility’s interconnection requirements:
- National Electrical Code (NEC) Article 690, Solar Photovoltaic Systems
- NEC Article 705, Interconnected Electric Power Production Sources
- NEC Article 706, Energy Storage Systems
- NFPA 855, Installation of Stationary Energy Storage Systems
- International Fire Code and IRC rooftop access and setback provisions
- UL 1741 for inverters and IEEE 1547 for interconnection
How licensing works. Engineering drawings must be sealed by a Professional Engineer licensed in the state where your project is located. PE Engineer works with a network of state-licensed PEs, so every set is reviewed and stamped by an engineer with an active license in the state where your project is located. Their name and license number appear on the seal, exactly as your building department requires.
Related services
Solar Structural LettersStamped solar structural letters confirming the roof can carry the PV array, with attachment spacing, uplift checks and reinforcement details when needed.Explore More
Electrical PlansElectrical load calculations, panel schedules, one-line diagrams, lighting and power plans prepared to the NEC and sealed by a licensed PE.Explore More
Carports & CanopiesStamped carport, RV cover, shade structure and commercial canopy designs, with columns, footings and anchors sized for uplift, snow and wind.Explore MoreFrequently asked questions
Do solar permit plans need a PE stamp?
It depends on the jurisdiction and the system. Many building departments require a sealed structural letter for rooftop arrays, and commercial and larger systems often need sealed electrical drawings. Some cities accept unsealed residential plans. We confirm what your jurisdiction requires and provide sealed drawings where needed.
What is the 120 percent rule for solar?
It is the common name for an NEC limit on load-side connections. The main breaker rating plus the solar breaker rating generally cannot exceed 120 percent of the panel busbar rating, with the solar breaker at the opposite end from the main. If a panel fails, we evaluate derating, supply-side connection or an upgrade.
Can you prepare plans for my installer's equipment?
Yes. We design around the listed modules, inverters, optimizers, racking and batteries your installer has chosen, and include their data sheets in the set. If a product does not work with the site conditions, such as string voltage in a cold climate, we tell you before the plans are submitted.
Do you provide the structural letter too?
Yes. We review the roof framing from photos and measurements, check the added dead load and wind uplift on the attachments, and provide a sealed structural letter or calculations. Submitting the electrical and structural documents together usually speeds up review.
Can you design battery storage additions?
Yes. We design battery and hybrid inverter systems to NEC Article 706 and NFPA 855, including the backup load panel, the transfer equipment, installation location and clearances. We also check that the existing PV system and main panel are compatible with the new equipment.
How fast can I get a solar plan set?
Most residential solar plan sets are delivered within a few business days of receiving complete information, and rush service is available. Commercial systems depend on size. We provide a fixed-fee quote, usually the same day, and plan-check revisions within the original scope are included.
Get your free solar pv plans proposal
Tell us where the project is and what you need. Attach any drawings, photos or plan-check comments. A licensed engineer reviews every request.
- Upload your filesPlans, sketches, photos or comments
- Get a fixed-fee proposalUsually the same day
- Receive stamped drawingsSealed by a PE licensed in your state