Solar Energy Toolkit: Solar PV Construction: Codes, Permitting, and Inspection
This section of Solar Energy: SolSmart’s Toolkit for Local Governments provides a general overview of the permitting and inspection process in the United States, followed by a discussion of best practices for improving these processes.
Solar Permitting and Inspection: An Overview
Solar installations must meet the permitting and inspection requirements for U.S. construction projects, which have been developed and refined over many decades. These requirements are issued to verify that projects conform to established construction codes.
The National Electrical Code (NEC), adopted throughout the United States and its territories, first included solar PV systems in 1984. The international building and fire codes adopted requirements for PV systems in 2012. Together, the electrical, building, and fire codes form the governing construction codes for local installations.
The codes, which are typically updated every three years, are not necessarily adopted as soon as they are published. State and local governments generally adopt the codes on schedules related to state and local governmental processes. For example, as of early 2019, most of the United States was either on the 2017 or 2014 editions of the NEC. However, a few state and local entities were enforcing the 2011 and 2008 editions.
The newer editions typically incorporate updates that better address issues concerning solar development. For example, starting with the 2015 editions of the International Building Code and International Residential Code, additional detail was provided on how to install PV systems on buildings. The International Energy Conservation Code provides details on how to calculate the benefits of PV systems and have allowed for more roof space for solar. Therefore, states and localities are encouraged to update their codes to more effectively regulate solar development.
In addition, many states and localities will amend these model codes prior to adoption. This variability makes it more difficult (and costly) for a solar installer to operate across multiple jurisdictions. Lead model code organizations, such as the International Code Council, work with a coalition of industry groups, including the Solar Energy Industries Association (SEIA), to encourage more consistent adoption of codes.
The vast majority of rooftop solar PV systems are installed on existing structures. Even though very few of these buildings were constructed specifically for installing solar equipment, many of them are well suited for PV systems. Furthermore, rooftop solar does not require the environmental permitting that is often necessary for ground-mounted installations.
The Project Approval Process: An Overview
The approval process for a solar energy project involves several basic steps. First, a permit application is submitted for review by a local permitting agency, known as the “enforcing agency.” Typically, the contractor installing the solar energy system will submit the permit on behalf of the building owner. Once the permit application is approved, the applicant has permission to build the solar installation. When the system is installed, the enforcing agency inspects it to ensure compliance with applicable building codes and local ordinances.
Along with applying for a permit, the contractor will contact the local utility provider to request permission to connect the solar installation to the local distribution grid. The solar PV system cannot be “turned on” until approval is granted by both the local agency and the local utility.
Well-informed solar installers and knowledgeable, well-trained local agency staff are critical to achieve an efficient permit approval process. Effective training is one of the most important steps that local governments and the solar industry can take to ensure efficient permitting.
REVIEWING THE PERMIT APPLICATION
Local enforcing agencies can be organized differently, but all have an established process for receiving, reviewing, and approving permits. Most often, the local enforcing agency reviewing the permit will be the building department.
In reviewing a permit, the enforcing agency applies state and local construction code requirements, as well as additional local requirements that apply to solar energy installations. In many cases, the local agency must interpret how state requirements apply to certain buildings.
The enforcing agency must verify that the installation complies with structural requirements, electrical requirements, and applicable fire safety provisions.
Structural Requirements. Rooftop solar installations add weight, commonly referred to as a “dead load.” This additional weight must be accounted for to ensure the solar installation is safe. Roof structures are also designed to carry temporary construction loads, known as “live loads,” which become a factor when the installation team is installing the system. The cost and complexity of adding solar panels will depend on the structure of the building and roof.
Solar panels may also impose loads generated by seismic forces and, in some areas, by snow accumulation. Solar panels must also resist wind forces. The International Building Code and the International Residential Code now provide details on how to calculate the loads that PV systems add to a building.
To ensure that installations meet these structural requirements, enforcing agencies may consult simplified structural guidelines, which are available on the SolSmart website. The guideline criteria indicate when a system does not require project-specific structural calculations. These guidelines include requirements in the following areas: general site and array; roof information; array mounting; member-attached array; and sheathing-attached array. Each category has a set of requirements that must be complete in order to apply for simplified solar permitting. The requirements can be checked without hiring an engineer, but if the requirements cannot be completed the installer may need to hire an engineer to provide structural calculations and/or details, stamped by a design professional to address the unchecked items.
Electrical Requirements. The National Electrical Code applies to many components of a solar system, including but not limited to the panels, modules, wire, inverters, connectors, and disconnects. Most of the major electric components of a solar installation are certified to meet product standards for solar PV systems or related electrical standards. Since these certifications provide the necessary safety testing, a local jurisdiction does not need to perform its own evaluations on the equipment and need only verify that the proper certifications were achieved. The NEC outlines a process for installing the components of a solar energy system in a safe manner. Components that are certified and tested for solar PV installations must be installed in accordance with the NEC and the manufacturer’s installation instructions.
Most residential solar PV systems are very simple from an electrical standpoint, and they can be designed by a solar or electrical contractor. In some circumstances, an electrical engineer may be required, and the enforcing agency determines if this is necessary based on the complexity of the system.
Fire Classification, Safety, and Roof Access and Pathway Requirements. Buildings throughout the United States are required to have a fire-resistant roof covering. The International Building and Residential Codes recognize three fire-resistant roof ratings: Classes A, B, and C. These ratings determine how fire-resistant a roof must be in order to meet code, depending on the type of construction, occupancy, or geographical location of the building. Roof materials with a Class A fire rating can withstand a high exposure to fire without allowing penetration or ignition of the structure, while Class B and C materials have a lesser ability to withstand fire. Class C is the minimum fire rating for all roof materials installed on buildings throughout the country. The building code requires all assembly occupancy buildings, such as churches and community centers, to have at least a Class B fire-rated roof. As of 2015, a roof-mounted solar PV system must have a fire-resistant rating that is the same as the minimum required rating for the building where it is installed.
Solar installations must also allow for fire department smoke ventilation operations. The International Building, Residential, and Fire Codes outline the requirements for a roof access point and clear access points along the roof. The installation of solar PV systems may be subject to additional provisions adopted by the local enforcing agency.
FIRE SERVICE APPROVAL
In many communities, the enforcing agency coordinates directly with the fire department or fire district (a local authority organized to provide fire services) to ensure the fire safety of solar projects. Many jurisdictions have established a memorandum of understanding between the fire authority and the local government, which allows the government building official to determine and approve fire safety requirements. In circumstances where the fire district is separate from the city or county government and no MOU is established, applicants should contact the local fire district early in the planning stages of a PV installation to determine if there are any unique requirements or approval processes within the jurisdiction.
Best Practices for Solar Permitting
Since solar energy systems are new to many communities, the construction process may be unfamiliar, leading enforcement staff to be more cautious than they might be for other projects. Unfortunately, this can lead to a slower and more complicated permitting process, which can significantly increase the cost of a solar energy system.
A simplified permitting process helps address this problem. The term “simplified permit process” refers to an organized permitting process by which a majority of small photovoltaic (PV) systems can be permitted quickly and easily. It is intended to simplify the structural and electrical review of a small PV system project, establish guidelines to determine when a PV project is within the boundaries of typical, well-engineered systems, and minimize the need for detailed engineering studies and unnecessary delays. The streamlined process is not intended to circumvent the engineering process; it is intended to show clear conformity to code requirements.
The SolSmart website provides guidelines for local governments to create a standardized process to review small-scale PV permit applications. This template can be followed by any community, irrespective of their solar experience. The simplified permitting format reduces these costly delays and makes the process easier for local governments, the industry, and solar consumers. An effective, streamlined permitting process will follow best practices related to inter-departmental coordination, cross-training staff, online permitting checklists, and an online submittal and approval process. View the SolSmart Simplified Solar Permitting Guide here.
When several different departments review the permit application package, this often lengthens review times. A simplified permit process authorizes one individual to conduct the review, rather than multiple departments. One way to accomplish this is through a memorandum of understanding (MOU) with each of the departments that traditionally review a permit package. When necessary, more complicated projects can still include review and signoff from multiple departments.
For instance, it is common for the planning department to review a solar project to see if it meets the aesthetics guidelines of the community. Rather than evaluating each project separately, it is more efficient to establish a set of requirements, allowing the planning department to automatically approve the project if these requirements are met. An example of such requirements is as follows:
- Solar panels, where visible from the ground, are mounted parallel to the roof surface.
- The maximum height of panels above the roof is 10 feet.
- Solar panels do not extend past the roof plane.
Another department that may want to review a solar permit request is the fire department. Normally, the fire department does not get involved in enforcing construction codes for residential buildings. However, concerns over the unique nature of solar projects may lead some fire departments to become part of the review process. Again, the best way to streamline the process is to set up a MOU with the fire department and determine a set of requirements that, if followed, do not require additional fire service review.
Staff training on the solar permitting and inspection processes is often a challenge for local jurisdictions. Personnel must cover a multitude of different areas of construction. It is generally most efficient to designate a small number of people in each jurisdiction who are knowledgeable about solar projects, including one or two key individuals and one or two others to provide backup.
ONLINE PERMITTING CHECKLIST
One very effective way to simplify the permitting process is for local governments to provide all necessary information online. This saves time not only for contractors, but also for local government personnel. By providing simple web-based resources, the jurisdiction can save considerable printing costs. Online resources should include the forms to request a permit, as well as an online checklist for the permitting process.
ONLINE SUBMISSION AND APPROVAL PROCESS
Many jurisdictions have pioneered online submittals and permit approvals. While this requires more technical resources than simply posting documents, an online submittal process is often a more efficient way of processing permit applications. The process could be as simple as sending emails with filled-in electronic forms, or as complex as having a self-verifying process where the computer essentially performs the permit review. Ultimately, the process needs to save time for all parties if it is to be of value. Currently, it is rare for a jurisdiction to have an online submittal process only for solar. Normally, if a jurisdiction is using online submittals and approvals for other types of construction, a simplified permitting process for solar will easily fit into the required framework.
REGIONAL UNIFIED PERMITTING PROCESSES
Many regions throughout the United States have organizations that share information with the goal of developing a consistent permitting process for a wide range of construction projects. These organizations should consider developing a consistent, streamlined process for permitting solar PV projects. If each jurisdiction has different construction practices and processes, it can be challenging for solar developers to keep up with different rules for different jurisdictions. Large solar companies have staff dedicated to tracking the requirements in the communities where they work, but small businesses may not have the resources to do so.
PERMIT FEE STRUCTURES
Permit fees are a common source of frustration for communities across the country. Some communities have been encouraged to charge little or nothing for solar permits as an incentive for new installations. While this is beneficial for solar projects, it can create animosity within a building department, which usually depends on permit fees for funding. A better approach is to review the fee structures within a community and establish fees that are commensurate with projects of a similar scope, such as the installation of an air conditioning system (where fees may range from $75 to $200).
As they review and improve the solar permitting process, local governments should seek input from businesses, community groups, electric utilities, and other interested parties. Even the best designed process will have aspects that do not work well. Making adjustments based on stakeholder input will ensure the process is working best for the community.
Best Practices for Inspection
After a developer receives the permit and installs the solar energy system, an inspector from the local enforcing agency physically inspects the installation. The field inspection ensures the solar technology has been installed properly and according to the approved plans. Once the system has passed the final inspection, the project can proceed to final utility approval and then begin official operation.
Inspections verify that an installation is compliant with building and electrical codes and fire safety requirements. To ensure building code compliance, an inspection will verify proper material selection, soundness of structural support, and secure attachment to the roof or ground. Inspection of a solar PV installation’s electrical system often focuses on wiring methods, circuit protection, grounding, and safety signage. The fire safety inspection may include verifying the labeling of equipment and ensuring sufficient space for firefighters to access the building.
MAKING INSPECTIONS WORK BETTER
A common issue within the construction industry is that inspectors will interpret the codes in different ways. Solar energy systems are not immune to these issues, but local inspection guidelines can make the process run more smoothly. An effective strategy to avoid this problem is for local governments to develop inspection checklists. Posting the inspection requirements online allows installers to address them prior to the inspection. The checklist can be used by reviewers, inspectors, and installers.
Local governments can also improve the process for conducting an inspection, greatly reducing the time and expense it takes to install solar. Many jurisdictions can complete a site inspection within one or two days’ notice that construction of the solar installation is completed, while others may take longer. Similarly, some enforcing agencies set a narrow window of time for an inspector to visit a property. This saves the permit applicants time and money. Contractors often spend considerable time waiting to meet an inspector at a construction site, which can be a challenge for companies with several simultaneous projects. Local governments should develop processes that minimize travel time between inspections and limit inspection appointments to 1-2 hour windows. An automated online system to track and communicate inspection times for all parties can help serve a community’s needs.
As with the permitting process, online inspection requirements should be posted online to ensure the necessary information is easily accessible. This web-based resource will benefit the jurisdiction and the contractors. Online resources should include an online checklist for the field inspection process.
Finally, enforcing agencies should strive to eliminate intermediate inspections before the installation is complete. Instead, they should ensure compliance with all applicable rules and requirements during the final inspection.
LOCAL UTILITY APPROVAL
All solar PV installations need the local utility’s approval to connect into the electricity grid. This process is separate from the enforcing agency’s approval. Interconnection approval ensures that a solar installation will safely connect and operate on the grid. Many utilities now install a meter upon system approval.
Understanding the utility’s requirements and process is very important. Utilities provide information about required interconnection agreements and any available financial rebates or incentives. To qualify for these incentives, property owners may be required to complete an energy audit before installing a PV system. Local utilities also differ on when the interconnection application is required. Some utilities may request that a contractor submit the application before a building permit is issued. Utilities may also require one or more on-site inspections of the project before approving the interconnection agreement, in addition to the inspections by the enforcing agency.
To help ensure an application is considered complete, permit applicants should contact their electric utilities to learn what specific information and forms must be included. Utilities often provide this information on their website as well. Some utilities have very accessible and straightforward interconnection processes, while other utilities may not.
In some jurisdictions, it is the installing contractor’s responsibility to notify the utility once the enforcing agency approves the installation. In other jurisdictions, it is the homeowner’s responsibility. Some jurisdictions automatically notify the utility when they have a successful PV inspection, which is a more involved process but can prove to be very efficient once it is set up.
The application process to connect to the grid can be challenging, often creating a bottleneck that can delay the overall project and increase costs for the customer, installer, and utility. Across the country, utilities are aiming to expedite the application process to reduce costs. Approaches that utilities are taking include reducing inspections by using them only if needed, and allowing applications to be completed online. Utilities spend considerable resources tracking PV installations, and an expedited process can make it easier and less costly to manage for all parties involved. The Interstate Renewable Energy Council (IREC) provides a Model Inspection Checklist for municipalities across the U.S. to utilize for rooftop solar systems.
Prepared by Bill Brooks and the SolSmart team, this resource provides local governments a standardized process for the review of small-scale PV systems. This process helps to simplify the structural and electrical review, establish guidelines to determine when a PV project is within the boundaries of typical, well-engineered systems, and minimize the need for detailed engineering studies and unnecessary delays. The webpage provides a step-by-step process for jurisdictions to utilize to develop a simplified permitting process. The format adheres to all building, residential, fire, and electrical codes set for PV systems published by the International Code Council (ICC) and the National Fire Protection Association.
Providing a set of requirements for the local solar permitting process (for both residential and commercial solar) on an easy-to-find local government webpage represents a major step toward overcoming informational barriers. An online solar permit checklist can be a simple way for a community to accelerate permit approval timelines and save staff time. The goal of a permitting checklist is to provide clear and transparent information that will reduce the number of inquiries from solar installers and improve application quality. The checklist does not need to take the exact form of this template, but it should include the basic information an installer, developer, or property owner would need to know in order to receive approval for the installation of a residential solar PV system. Such checklists typically detail all the plans and forms required for approval and system design requirements.
Providing an online list of inspection requirements will reduce informational barriers between inspectors and solar installers, helping to ensure that all items in the inspection process have been adequately addressed before inspectors arrive on site. These checklists can be used to highlight “common mistakes” made by installers.
While requiring a single application form under existing permitting processes represents an improvement over requiring both a building and electrical permit, it may still be more time consuming to complete, review, and approve permits via a process not specifically designed for solar. Developing a solar-specific permit (or combining building and electrical permits with revisions to collect information unique to solar energy systems) and posting application materials online can save time and money for both those completing the forms (and their customers) and the local government staff reviewing and approving these applications.
IREC provides a model checklist for municipalities to adopt an inspection checklist that can be used for streamlined on-site verification of compliance with code requirements for inspectors.
 “Explore the 2017 NEC,” National Fire Protection Association, Accessed August 12, 2019. https://www.nfpa.org/NEC/About-the-NEC/Explore-the-2017-NEC.
 “NFPA 1 Fire Code,” National Fire Protection Association, Accessed August 12, 2019. https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=1.
 “Explore the 2017 NEC,” National Fire Protection Association, Accessed August 12, 2019. https://www.nfpa.org/NEC/About-the-NEC/Explore-the-2017-NEC.
 Friedman, Barry, Kristen Ardani, David Feldman, Ryan Citron, Robert Margolis, Benchmarking Non-Hardware Balance-of-System (Soft) Costs for U.S. Photovoltaic Systems, Using a Bottom-Up Approach and Installer Survey – Second Edition, October 2013. https://www.nrel.gov/docs/fy14osti/60412.pdf.
 Brooks, Bill, “Expedited Permit Process for PV Systems: A Standardized Process for the Review of Small-Scale PV Systems”, July 2012. http://solarabcs.org/about/publications/reports/expedited-permit/pdfs/Expermitprocess.pdf.
 McAllister, Richard, David Manning, Lori Bird, Michael Coddington, Christina Volpi, New Approaches to Distributed PV Interconnection: Implementation Considerations for Addressing Emerging Issues, February 2019. https://www.nrel.gov/docs/fy19osti/72038.pdf