Kane County, IL Outdoor Lighting: Light Trespass & Shielding (2026)

The LI (Light Industry) district under Kane County's zoning ordinance is meant for manufacturing, assembling, processing, storage and research uses that do not create nuisances or hazards for neighboring land. Section 25-11-1 requires every use in the district to meet the performance standards spelled out in section 25-11-1-5, covering noise, smoke, particulate matter, toxic or noxious matter, odors, fire and explosive hazards, vibration, glare and heat, and radiation. Subsection G, Glare-Heat-Flash, is the light-trespass rule: "any operation producing intense glare, heat or flash shall be performed within a completely enclosed building in such manner as not to create a nuisance or hazard along lot lines." In practice, arc welding, foundry work, furnaces, high-intensity process lighting or any operation throwing off a bright flash or heat signature cannot be run in the open; the building's walls have to contain it so a neighbor standing at the property line sees and feels nothing.

Compliance is checked at the permit stage. Section 25-11-1 lets the zoning enforcing officer demand certification from an approved testing laboratory showing the operation meets the applicable performance standards before a building permit is issued or a change of use approved, and no use already operating on the ordinance's effective date can be altered in a way that pushes it out of compliance. The standard applies along every lot line in the LI district; it does not reach residential floodlights, farmyard security lighting or commercial parking-lot fixtures, which sit under separate sections of the code, only industrial operations sited in the LI zone.