Tiny home rules in McHenry County, IL — covering tiny houses on wheels (THOWs), park model RVs, and tiny home on foundation builds — determine where they are legal and how they get permitted.
McHenry County has no separate tiny-home category. A tiny home can only be a legal second dwelling if it qualifies as an ancillary dwelling unit under the UDO. Mobile home trailers and recreational vehicles are expressly barred from serving as an ADU.
The UDO does not define "tiny home," so a small detached dwelling is regulated as an ancillary dwelling unit under § 16.56.030O or as a principal dwelling. As an ADU it must meet building code, county Department of Health well/septic rules, the two-bedroom cap, owner occupancy, the one-per-lot limit, and (if detached) a 900-square-foot footprint cap and 35-foot height limit. An accessory structure may not be used as a dwelling unless it qualifies as an ADU. Critically, mobile home trailers and recreational vehicles cannot be used as an ancillary dwelling unit, so a towable tiny home on wheels does not qualify.
Using a non-conforming tiny structure as a residence is a zoning violation; the Zoning Enforcement Officer can require it be removed or legalized as an ADU.
Other ordinances people look up for this city. Green dot = verified primary-source excerpt.
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Crystal Lake collects yard waste and food-scrap compost weekly at the curb from April 1 through November 30. Leaves and grass must go in biodegradable paper ...
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Illinois' Homeowners' Native Landscaping Act bars community associations from banning native-species plantings that are kept free of weeds and don't encroach...
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Neither Crystal Lake nor McHenry County prohibits residential rain barrels or rainwater collection, and Illinois has no statewide ban. The McHenry County Sto...
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Crystal Lake uses a color-coded water-conservation system. During a declared 'Yellow' condition, odd-numbered addresses water on odd dates and even addresses...
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Crystal Lake Chapter 526 lists noxious weeds - burdock, ragweed, thistle, poison ivy, wild mustard and others - plus any unmanaged vegetation as nuisance gre...
See how McHenry County's tiny homes rules stack up against other locations.
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