Lake Bluff homeowners would face caps on outdoor light brightness, color temperature and overnight hours under a draft ordinance two village boards reviewed Sept. 15.

The Village of Lake Bluff's Architectural Board of Review (ABR) and Joint Plan Commission and Zoning Board of Appeals (PCZBA) held a joint work session at Village Hall to evaluate the proposed exterior lighting regulations. John Barentine, principal consultant with Dark Sky Consulting, LLC, presented the draft and fielded questions from both bodies, according to the village's meeting packet.

No formal vote or recommendation was taken. The boards gathered initial feedback and opened public discussion.

What the draft would require

The ordinance divides Lake Bluff into three lighting zones. Parks would fall under LZ0, allowing no ambient lighting. Single-family residential areas would be classified LZ1, permitting low ambient lighting.

Commercial and other non-residential districts would be LZ2, for moderate ambient lighting.

For single-family homes in LZ1, each fixture could produce no more than 1,400 lumens. The total for an entire residential lot would be capped at 10,000 lumens per acre.

Non-residential properties in LZ2 could use fixtures up to 17,500 lumens, with a lot cap of 50,000 lumens per acre.

Every outdoor light source would be limited to a maximum color temperature of 3,000 Kelvin, blocking the harsh blue-white LEDs common in newer installations. All new exterior fixtures would need to be fully shielded, directing light downward rather than into the sky or neighboring yards. Unshielded floodlights, wallpacks, drop-lens fixtures and barn lights would be prohibited.

Curfews and spillover limits

On residential lots, outdoor lighting would need to be off between 11 p.m. and 5 a.m. Sports field lights would have to be extinguished by 10 p.m. or one hour after play ends, whichever is later.

At any property line next to a residential lot, light spillover could not exceed 0.5 foot-candle. The limit rises to 1 foot-candle between non-residential properties.

Flashing, blinking, rotating and laser lights would be banned.

Exemptions and grandfathering

Holiday lights would be exempt from Nov. 15 through Jan. 30. Emergency lighting, government-required fixtures and underwater illumination also fall outside the rules. Small solar lights producing 100 lumens or less would not need timers.

Existing non-residential properties that don't meet the new standards would have four years after adoption to comply. Single-family homes would be presumed compliant at adoption unless a major renovation triggers review.

Two years in the making

The Sustainability and Community Enhancement Ad Hoc Committee (SEC), chaired by Village Trustee Brian Rener, spent roughly two years developing the draft with Barentine's technical guidance. The effort traces to the village's Sustainability Plan, which flagged outdoor lighting regulation as a high-priority action item.

The plan quotes University of Illinois researcher Steve Long: "We're gambling with our future in what we're doing to the environment."

A staff memorandum prepared by Village Administrator Drew Irvin and Max Morgan, assistant to the village administrator, for the Village Board's June 8 Committee-of-the-Whole meeting noted that Lake Bluff's current approach is limited compared to similar communities. Commercial lighting goes through design review, but residential exterior lighting generally faces no specific performance standards.

The Village Board expressed general support at that June 8 session and referred the proposal to the ABR and PCZBA for further review.

Local examples already in place

At the Village Board's June 22 meeting, Trustee Rener pointed to light-pollution controls already operating in Lake Bluff. The fire station's exterior lighting was retrofitted with low-glare fixtures that focus light on pavement rather than the sky. Lake Bluff Middle School, a LEED Silver building, uses low and dim parking lot lighting.

Village President Charlot recalled harsh blue lighting near the library that had produced glare into neighbors' yards, leading to subsequent mitigation.

The village's Sustainability Plan notes that Lake Bluff's nighttime light pollution level is among the lowest near Chicago, comparable only to the Fox River area in western Lake County. No date has been announced for the next public hearing or Village Board vote on the ordinance.