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How to Avoid Permit Rejections- Top Solar Design Mistakes to Watch Out For
Permit rejections are one of the most common setbacks in solar installation projects. After spending time on system design, client coordination, and scheduling, a single error in the design plan can bring everything to a halt. Most of the time, these rejections stem from common and avoidable mistakes.
To help you stay ahead, here are the top solar design errors that often lead to permit rejections, along with simple ways to avoid them.
1. Submitting Incomplete or Incorrect Plan Sets
Permitting authorities require complete and accurate documentation. If your submission is missing key details, like panel layout, wiring diagrams, or equipment specifications, it may get rejected.
- Including a full site plan with accurate panel placement
- Attaching single-line and three-line electrical diagrams
- Providing spec sheets for all equipment
- Including mounting and racking information
2. Not Following Local Codes and Regulations
Every jurisdiction has its own specific permitting rules. Relying solely on national codes without checking local guidelines often leads to rework.
- Researching local permitting requirements before you start designing
- Calling or emailing the local AHJ if you're unsure
- Using services familiar with different state and city regulations
3. Improper Structural Analysis
Solar panels add weight to a roof. Without proof that the structure can support the added load, especially in areas prone to wind or snow, your design might get rejected.
- Including a structural assessment performed by a licensed engineer
- Using Site Specific Memos and stamped engineering documents
- Adjusting panel placement or mounting style based on roof limitations
4. Electrical Miscalculations
Permit reviewers often flag issues with wire sizing, conduit fill, breaker capacity, and inverter selection. Errors here can be safety concerns.
- Following National Electrical Code (NEC) requirements closely
- Verifying conductor sizes, voltage drops, and overcurrent protection
- Using licensed professionals to review and stamp your electrical plans
5. Missing Rapid Shutdown Components
Rapid shutdown devices are required on most rooftop solar systems to protect first responders. Omitting these from your design can delay approval.
- Including rapid shutdown systems compatible with your inverter and modules
- Clearly showing shutdown devices in your electrical diagram
- Labeling equipment and including specs in your submission
6. Poor Panel Placement and Shading Oversights
Shaded panels underperform, and some jurisdictions ask for proof of expected system output. Improper placement can raise concerns about efficiency.
- Performing a shade analysis or using simulation tools like PVsyst
- Adjusting panel location for optimal sunlight exposure
- Including shade reports in your permit package when needed
7. Not Respecting Fire Setback Requirements
To allow access for emergency responders, fire codes often require clear roof paths and spacing between panel groups.
- Reviewing the local fire code (or IFC guidelines)
- Leaving proper access and ventilation space in your layout
- Labeling setbacks clearly in your site plan
8. Ignoring EV Charger Requirements
As EV chargers are increasingly paired with solar, they must be included in your electrical design when relevant. Missing EV-related documentation can delay approval.
- Preparing a separate EV Permit Plan Set
- Including updated load calculations and wiring diagrams
- Coordinating with utility companies if necessary
In Summary
Permit rejections can slow down your solar projects and increase costs. But most issues are preventable with careful planning and attention to detail. By understanding common mistakes and proactively addressing them in your design process, you can reduce delays, improve approval rates, and keep your projects moving forward.
Need help with solar permit designs?
From complete Solar Permit Plans to Structural & Electrical Stamping, Site Surveys, EV Plan Sets, and more, we offer fast, reliable services to help you get permits approved the first time.
