Property Maintenance in McHenry County, IL (2026)

2 rules for unincorporated McHenry County, Illinois.

Verified from official government sources

Note: These county rules apply to unincorporated areas of McHenry County. If you live within an incorporated city, that city's own rules apply: see the city list below.

Property Blight

Unincorporated McHenry County's amended building code lets the building official declare any structure or piece of equipment unsafe for inadequate egress, sanitation, fire hazard or illegal occupancy, and every unsecured vacant building is automatically unsafe. Owners get written notice to repair or demolish; ignoring it sends the case to the State's Attorney, and imminent danger lets the official order occupants out immediately.

McHenry County Unsafe & Vacant Structure Rules

Significant Restrictions

McHenry County Code § 15.04.010 (IBC § 116.1, Conditions)

[A] 116.1 Conditions. Structures or existing equipment that are or hereafter become unsafe, insanitary or deficient because of inadequate means of egress facilities, inadequate light and ventilation, or that constitute a fire hazard, or are otherwise dangerous to human life or the public welfare, or that involve illegal or improper occupancy or inadequate maintenance, shall be deemed an unsafe ...

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Vacant Lot Maintenance

Unincorporated McHenry County law makes it a public health nuisance to let noxious weeds stand within 150 feet of any property line, whether the lot is built on or vacant. Section 8.04.080(E) names specific weeds, including Canada thistle and Johnson grass, and the McHenry County Department of Health enforces the rule with written notice, a cure period, and misdemeanor fines.

Vacant Lot Weed Nuisance in McHenry County

Some Restrictions

McHenry County Public Health Ordinance §§ 8.04.080(E), 8.04.060

The following are declared public health nuisances prejudicial to the public health: ... E. Failing to eradicate all noxious weeds within 150 feet of any property line. ... "Noxious Weed" means Canada thistle (Cirsium arvense), perennial Sowthistle (Sonchus arvensis), Musk Thistle (Carduus nutans), and perennial members of the sorghum genus including Johnson grass (Sorghum halepense), and Sorgh...

Full ordinance details →Official source ↗

All McHenry County ordinances

See every category we cover for McHenry County: parking, noise, fences, fires, animals, pools, and more.

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