McHenry County, IL Solar Energy: Panel Permits (2026)

McHenry County's Planning & Development Department reviews solar installations through Section 15.08.010's amendment to Section R324, Solar Energy Systems, part of the same 2021 IRC amendment package, Ordinance O-202211-10-052, effective January 1, 2023, that governs all residential construction permits. Photovoltaic systems must be 'designed and installed in accordance with the McHenry County Unified Development Ordinance...and NFPA 70,' and every inverter 'shall be listed and labeled in accordance with UL 1741'; systems tied to the grid must use inverters specifically listed for utility interaction. Solar thermal systems installed for water or space heating are separately routed to the Unified Development Ordinance and the International Fire Code rather than the photovoltaic provisions.

Structural review is not optional. R324.4.1 requires roof structures supporting photovoltaic panels to be engineered for two load cases: dead load including the panel weight plus snow load per Table R301.2(1), and dead load excluding panel weight plus roof live load or snow load, whichever governs, per Section R301.6. For ground-mounted arrays, R324.7.1 sets a fire separation distance of 7 feet 0 inches from any other accessory or principal structure on the lot, unless the Unified Development Ordinance requires more.

Because solar work is folded into the standard building permit rather than issued as its own category, the same Planning & Development plan review, County Board fee schedule, and inspection sequence used for other residential alterations applies to a photovoltaic installation.