Cook County, IL Outdoor Lighting: Light Trespass & Shielding (2026)
Key Facts
- Rule
- Sensor lights must not trigger off-property
- Source clause
- Sec. 2-342(5)
- Applies to
- County-owned/operated fixtures only
- Adopted
- Ord. No. 12-O-12, 2-15-2012
- Qualifier
- Required only "where practical"
Summary
Cook County's Lighting Ordinance targets motion-activated security fixtures directly: sensor-activated lights on County property "should not be triggered by activity off the subject property" (Sec. 2-342(5)), and installations should pair sensors with timers or photocells to cut power in daylight. The rule binds County-operated lighting only, not a homeowner's floodlight.
(5)Where practical, outdoor lighting installations are to include timers, dimmers, sensors, or photocell controllers that turn the lights off during daylight hours to reduce overall energy consumption and eliminate unnecessary lighting. Sensor activated fixtures should not be triggered by activity off the subject property.
Full Breakdown
Section 2-342(5) of the Cook County Lighting Ordinance (Ch. 2, Art. V, Div. 1, adopted Ord. No. 12-O-12, February 15, 2012) provides: "Where practical, outdoor lighting installations are to include timers, dimmers, sensors, or photocell controllers that turn the lights off during daylight hours to reduce overall energy consumption and eliminate unnecessary lighting. " That second sentence is the County's specific answer to nuisance security lighting - a motion-sensor floodlight on County property is not supposed to fire every time someone walks past on the sidewalk or a neighboring parcel; its sensitivity and aim must be contained to the property it serves.
" As with the rest of the Ordinance, Section 2-341(d) limits the reach of Section 2-342(5) to "new and replacement lighting on roadways, developments, properties, buildings or structures under the jurisdiction of Cook County Departments" - so the sensor rule governs County parking lots, facilities and grounds, not a resident's or business's own motion-light installation. Section 2-341(f) again applies the most-restrictive-law rule where other County, state or federal regulation conflicts.
Violations & Fines
No fine or citation scheme targets private security-light owners under this section; compliance runs through each County Department's own "policies and procedures" (Sec. 2-341(d)). Section 2-343 exempts emergency, construction, and special-event lighting from the sensor-aiming standard, and the "practical" qualifier in Section 2-342(5) means the requirement is not absolute where site conditions make full containment infeasible.
Frequently Asked Questions
What does Cook County's Ordinance say about motion-sensor lights?
Does this rule cover a homeowner's security floodlight?
Is the sensor requirement mandatory in every case?
Sources & Official References
Other rules in Cook County
Compare Cook County to another location·View the Illinois outdoor lighting overview
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