Building Safety in McHenry County, IL (2026)
5 rules for unincorporated McHenry County, Illinois.
Verified from official government sources
Fire Sprinkler Requirements
Unincorporated McHenry County does not require automatic fire sprinklers in new one- and two-family homes or townhouses. The county's amended 2021 International Residential Code deletes that mandate outright, and even attached-garage sprinkler requirements are struck from the code. Builders who install a system voluntarily still must follow Illinois Plumbing Code and NFPA 13D design rules enforced by the Building Official.
McHenry County: No Fire Sprinkler Mandate for Homes
Few RestrictionsMcHenry County Code § 15.08.010 (IRC § R313, Automatic Fire Sprinkler Systems)
R313.1 Townhouse automatic fire sprinkler systems. An automatic residential fire sprinkler system shall not be required in townhouses. R313.1.1 Design and Installation. Where provided, automatic residential fire sprinkler systems for townhouses shall be designed and installed in accordance with the Illinois Plumbing Code and NFPA 13 D. R313.2 One- and two-family dwellings automatic fire systems...
Childcare Center Rules
In unincorporated McHenry County, a stand-alone day care center is a permitted principal use only in the B-1, B-2, B-3, O and I-1 zoning districts under UDO § 16.56.030(L), not in any agricultural or residential district. Operators must meet state licensing and building-code rules and provide one drop-off space per eight enrolled children.
Day Care Centers in Unincorporated McHenry County
Some RestrictionsMcHenry County UDO § 16.56.030(L)
L. Day Care Center. 1. Day care centers shall meet all state regulations including, but not limited to, maximum occupancy and minimum outdoor area requirements, licensing, and health, safety. and building code requirements. 2. One (1) drop-off space is required for every eight (8) day-care recipients, based on maximum enrollment. The drop-off space shall be located immediately adjacent to the f...
Building Permits
Unincorporated McHenry County enforces the 2021 International Building Code with local amendments under County Code § 15.04.010. Nearly every construction project needs a permit from the Department of Planning and Development, with only narrow exemptions for small sheds, low open fences, short retaining walls, and similar minor work.
When McHenry County Requires a Building Permit
Some RestrictionsMcHenry County Code § 15.04.010
SECTION 105 PERMITS a. Revise Section 105.2 "Work exempt from permit. Building: Exemption 1." to read as follows: 1. One-story detached accessory structures used for tool and storage sheds, playhouses, and similar uses, that have a maximum floor area of one-hundred fifty (150) square feet and are not located in a floodplain or wetland and comply with all requirements of the McHenry County Unifi...
Electrical Permits
Any electrical service work in unincorporated McHenry County, new wiring, a service change, or equipment modification, needs a permit from the Planning & Development Department before work starts under the county's adopted 2020 National Electrical Code. Minor repairs like lamp replacement or plugging into an existing outlet are exempt, but a permitted job must pass a building-official inspection before the utility is authorized to energize it.
McHenry County Electrical Permit Requirements
Some RestrictionsMcHenry County Code § 15.12.010 (NEC Article 90.4, Permits/Exemptions/Inspections)
(A) Permits. Electrical wiring and equipment associated with an electrical service shall not be installed, replaced or otherwise modified without first submitting a permit application, securing approval and a permit through the McHenry County Planning & Development Department. (B) Exemptions. It shall not be necessary to obtain a permit for minor repair work. ... (C) Inspections. Electrical wir...
Plumbing Permits
Plumbing work anywhere in unincorporated McHenry County is governed by the Illinois State Plumbing Code, 77 Ill. Adm. Code §§ 890 et seq., adopted by the County Board word-for-word with no local amendments. The state code prevails over any conflicting county rule, and permits for covered plumbing work run through the Department of Planning and Development under the same Title 15 building-permit framework.
McHenry County Plumbing Permits: State Code Applies
Some RestrictionsMcHenry County Code §§ 15.24.010, 15.24.020
§ 15.24.010 ADOPTED. The Illinois State Plumbing Code, 77 Ill. Adm. Code §§ 890 et seq., as amended from time to time, is hereby adopted by reference in its current form, without addition, modification, exception or amendment. § 15.24.020 CONFLICT WITH OTHER CODES. If there is any conflict between this code and other codes adopted by the County, the Illinois State Plumbing Code provision shall ...
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