Solar Photovoltaic (PV) Permit in Billings, Montana

Billings requires a solar photovoltaic (pv) permit for: Detailed site plan required showing home/structure location, electrical service meter, main service panel, interconnected sub-panels, and all PV components; must show structure square footage, total panel square footage, and confirm IRC-required fire access pathways and ridge setbacks; Mounting system evaluation by a Montana-licensed professional engineer confirming the structure supports additional loads, using minimum 30 psf (non-reducible) roof snow load, 110 mph ultimate wind speed, and Exposure Category C; One-line diagram specifying PV system type, module count/layout, array circuit type, power output, conductor/conduit sizing, equipment grounding conductor, and fuse/breaker ratings; Interconnected components diagram showing which electrical panels the PV system backfeeds, bus ratings, and code reference from NEC Article 705 for each interconnection type, plus photos of the meter main and service/sub panels; Site-specific labeling diagram (not generic/typical) including the NEC 705.10 directory; Module specification sheets (UL 1703 listed) and inverter specification sheets (utility-interactive inverters must meet UL 1741 with ground fault protection and rapid shutdown compliance). If your project isn't listed, confirm with City of Billings Building Division at (406) 657-8270 before starting work.

In Billings, the published Building Permit Fee — valuation-based (same schedule as new construction; project bid value used as valuation) is: $30.00 minimum ($1-$1,000 valuation), scaling per the Residential and Commercial Building Permit Fees table. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Plan review for a solar photovoltaic (pv) permit in Billings typically runs 4–7 business days. This is an estimate, not a published figure — confirm current review times with City of Billings Building Division at (406) 657-8270.

You'll need: Solar-Photovoltaic System Plan Requirements Submittal; Building/Electrical Permit Application. See the required-documents checklist on this page for details on each.

Billings requires 2 inspection(s) for a solar photovoltaic (pv) permit, in order: Rough Electrical, Final. Schedule each through City of Billings Building Division ((406) 657-8270).

Apply through City of Billings Building Division at 316 N 26th St, 5th Floor, Billings, MT 59101. Phone: (406) 657-8270, email: permits@billingsmt.gov. Office hours: Building Division front counter, 5th Floor, City Hall, 316 N. 26th St., Billings, MT 59101 (inspection requests: inspections@billingsmt.gov or 406-657-8270). Official information: https://www.billingsmt.gov/67/Building.

Billings, Montana has adopted: Montana has a mandatory statewide building code administered by the Montana Department of Labor & Industry (DLI) Building Codes Bureau, amended by the Administrative Rules of Montana (ARM) Title 24, Chapter 301. Cities, counties, and towns may become 'certified' to locally administer permitting and inspection for all or part of the code (building, plumbing, electrical, mechanical, swimming pool, etc.); a certified local program's adopted code 'may include only codes adopted by the Building Codes Bureau' (ARM 24.301.202). Non-certified areas fall under direct state administration by the DLI Building Codes Bureau. Source: Montana DLI Building Codes Bureau, Certified City, County and Town Programs and Current Codes pages (bsd.dli.mt.gov/building-codes-permits).; Billings is a Montana DLI-certified jurisdiction for Building (B), Plumbing — Mechanical/Gas (P(M/G)), Electrical (E), Mechanical (M), and Swimming Pool (SP) within Billings city limits; certified program contact on file with DLI: Jessica Fust, (406) 657-8270. Source: Montana DLI Building Codes Bureau, Current Codes page (list of certified jurisdictions), bsd.dli.mt.gov/building-codes-permits/current-codes; 2021 International Building Code (IBC) — effective statewide June 11, 2022; adopted by City of Billings, last readopted September 1, 2022 per Administrative Order #150; 2021 International Residential Code (IRC) — effective statewide June 11, 2022; adopted by City of Billings per Administrative Order #150. Note: per the City's Adopted Codes page, IRC Chapters 11-14 and 16-43 are deleted in their entirety; IRC Chapter 15 (Exhaust Systems) is adopted as an alternative to the IMC for exhaust systems only, with all other mechanical-system requirements for detached 1-2 family dwellings and townhouses (3 stories or less) found in the adopted IMC; 2021 International Existing Building Code (IEBC) — effective statewide June 11, 2022; 2021 International Mechanical Code (IMC) — effective statewide June 11, 2022; adopted by City of Billings per Administrative Order #150; 2021 International Fuel Gas Code (IFGC) — effective statewide June 11, 2022; adopted by City of Billings per Administrative Order #150; 2021 International Energy Conservation Code (IECC) — effective statewide June 11, 2022; adopted by City of Billings per Administrative Order #150; 2021 Uniform Plumbing Code (UPC) — effective statewide June 11, 2022; adopted by City of Billings per Administrative Order #150 (Montana uses the Uniform Plumbing Code, not the International Plumbing Code); 2020 National Electrical Code (NEC) — effective statewide June 11, 2022; adopted by City of Billings per Administrative Order #150; 2021 International Swimming Pool and Spa Code (ISPSC) — effective statewide June 11, 2022; Billings is DLI-certified for swimming pool (SP) permitting; 2021 International Fire Code (IFC) — per City of Billings Building Division FAQ, current adopted code list; ICC A117.1-2017 Accessibility — effective statewide June 11, 2022 (state-adopted; referenced for commercial accessibility compliance); NFPA 99c, Standard on Gas and Vacuum Systems (medical gas), 2021 Edition — per City of Billings Adopted Codes page; All codes amended by the Administrative Rules of Montana (ARM) Title 24, Chapter 301. City of Billings Building Codes were last (re)adopted September 1, 2022 per Administrative Order #150. Local amendments apply — see the Billings overview page for the full list.

The City of Billings requires mounting-system engineering calculations to use a minimum 30 psf (non-reducible) roof snow load, an ultimate wind speed of 110 mph, and Exposure Category C. Source: City of Billings Solar-Photovoltaic System Plan Requirements (rev. 02/23).