What permits do you need to install solar panels?

Homeowners tend to picture a solar install as a crew, a ladder and a very sunny afternoon. The building department pictures a roof that has to carry new weight, an electrical system that now has two sources of power, and a firefighter who may one day need to cut a hole in that roof in the dark.

Both pictures are accurate. Only one of them issues permits.

What permits do you need to install solar panels?

For a typical residential rooftop system, you need an electrical permit for the array, inverter and connection to the house, and in most places a building permit or structural review for the roof attachment. Separately, the utility has to approve the interconnection before the system can be turned on.

Some jurisdictions combine the building and electrical sides into one solar application. Others keep them as two permits filed together. Either way, the reviewer is looking at the same questions, and the rest of this post walks through them.

The electrical permit

This is the permit every rooftop system needs. The reviewer wants to see how the power gets from the roof to the panel and the grid, and that every piece of equipment on that path is listed and correctly sized.

The electrical side of a plan set usually includes:

• A single-line diagram showing modules, inverter or microinverters, disconnects, the point of interconnection and, where net metering applies, the production meter
• Equipment spec sheets for modules, inverters, racking and rapid shutdown devices
• Wire, conduit and overcurrent sizing
• Grounding and bonding details
• A label plan showing which warning labels go where

The point of interconnection is where electrical review most often slows down. If the system backfeeds the main panel, the busbar and main breaker ratings decide whether the breaker fits as drawn, or whether the design needs a derate, a line-side tap or a panel change. A photo of the panel label during the site visit settles most of this before anyone draws anything.

The building permit or structural review

A rooftop array adds dead load and wind uplift to a roof that was not designed with it in mind. Most jurisdictions want proof the roof can take it.

What that proof looks like varies. Boston asks for a structural engineer's report confirming the condition of the roof on its Short Form solar filing. New York State's Unified Solar Permit asks for construction documents stamped by a New York registered architect or professional engineer, covering roof framing, the attachment method and site-specific calculations. Vancouver, Washington, requires engineering when the total dead load of the modules and mounting exceeds 4 pounds per square foot.

The building side also covers the roof layout: where the array sits, how it is attached, and how it leaves room for firefighters, which is the next section.

Fire access pathways and ridge setbacks

Codes based on the International Residential Code require clear pathways on the roof so firefighters can get from the eave to the ridge. The section was R324.6 in earlier editions and is R329.6 in the 2024 IRC. Under the 2024 text, as Larimer County, Colorado, summarizes it:

• At least two 36-inch pathways, on separate roof planes, from the lowest roof edge to the ridge, with at least one on the street or driveway side
• An 18-inch clear setback on both sides of a horizontal ridge for arrays covering no more than 33% of the roof's plan-view area, and 36 inches for larger arrays
• A higher 66% threshold for homes with an automatic sprinkler system
• A 36-inch pathway to any emergency escape and rescue opening

Local fire authorities amend these rules more than almost anything else in a solar permit. Larimer County's own guidance notes that the Poudre Fire Authority allows a reduced ridge setback in some cases. Check the local version before the layout is final, because moving a row of modules after the customer has seen the design is a harder conversation than drawing it correctly the first time.

Rapid shutdown

NEC 690.12 requires rooftop PV systems on buildings to have a rapid shutdown function, so the conductors on the roof can be de-energized quickly. Reviewers check it on the plans, and inspectors check it again on the roof.

On the plans, jurisdictions typically want to see the rapid shutdown devices, the location of the initiation switch, and the listing the system relies on. Vancouver's checklist, for example, asks for the rapid shutdown devices and control location, a note of the UL 3741 or UL 1741 listing, and a description of how shutdown is activated and complies with 690.12. The labels for the rapid shutdown switch and other equipment have to be shown on the plans and installed in the field.

Which edition of the NEC your jurisdiction has adopted matters here, because rapid shutdown requirements have changed between editions. Confirm the edition before the design goes out.

Zoning, historic review and local add-ons

Most rooftop systems never see a zoning board, but some do. New York's Unified Solar Permit, for example, is only available for systems that are not subject to an architectural or historical review board and do not need a zoning variance or special use permit. In New Jersey, a township such as Cherry Hill requires a zoning permit before the construction permit.

Then there are the local extras that are not in any model code. Boston asks for a signed homeowner waiver and site safety affidavit. Some towns on Long Island require a notarized affidavit about every structure on the property. Our Boston solar permit page and Yonkers solar permit page list the local requirements we have confirmed for those cities.

SolarAPP+ and standardized permits

In jurisdictions that use SolarAPP+, a qualifying system can be reviewed automatically and permitted the same day. SolarAPP+ covers detached one- and two-family homes and townhomes up to three stories, with a service rating of 400 A or less, busbars of 225 A or less, and systems up to 38.4 kW. Ground-mounted, ballasted, multi-family, commercial and homeowner-installed systems are out of scope and go through the normal process.

SolarAPP+ replaces plan review, not the inspection. The system still has to pass inspection in the field.

New York takes a different approach with its Unified Solar Permit, a standard application many municipalities use for eligible systems. Troy's version covers systems of 25 kW DC or less and commits to a permit decision within 7 calendar days of a complete application.

Utility interconnection is its own track

The utility does not issue the permit, but it decides when the system can turn on. The interconnection application usually starts before installation and finishes after the municipal inspection.

Eversource describes its residential process in three steps: the installer applies, the system is built, and at closeout the system is inspected by the municipality and the installer submits completion documents. Eversource then installs the meters and issues permission to operate. It says the whole process averages about 120 days from application, though timing varies.

The practical point is that a permit that sits open after installation does not only annoy the building department. It holds up the utility, which holds up the customer's first bill credit.

Where solar permits usually stall

The first-pass corrections we see most often on solar are the ones described in the six reasons permits get kicked back: a scope on the application that does not match the plan set, a contractor not yet registered with the city, homeowner or parcel details that do not match the city's records, and attachments the reviewer cannot read. To that list, solar adds three of its own:

1. Busbar math that does not work for the breaker as drawn
2. Pathways and setbacks drawn to the model code when the local fire authority amended it
3. Structural documentation that is missing a stamp, or stamped by someone not licensed in that state

All of these are cheaper to solve before filing than during plan check.

How TaskHatch helps

We file residential solar permits for installers, researching each jurisdiction's application, structural and fire access requirements before filing, and through SolarAPP+ wherever the city participates. Filing starts at $150 per project, and plan check comments are included. If the jurisdiction needs new documents from you, such as a revised layout or added engineering, the resubmittal is $75. Plan sets and PE stamps for systems up to 30 kW are available as separate line items, and inspection coordination through final is $100 per project.

Sources

• City of Boston: Install or replace solar panels
• City of Troy, New York: NYS Unified Solar Permit application
• City of Vancouver, Washington: Residential solar panel checklist
• Larimer County, Colorado: Residential solar array roof layout
• Spokane County, Washington: Solar photovoltaic systems handout (IRC R324.6)
• SolarAPP+ Help Center: What types of systems are eligible for SolarAPP+ review?
• Eversource: Solar interconnection