Lighting Regulations in Ada County, Idaho: Balancing Safety, Functionality, and Community Character

Introduction

Ada County, Idaho, established in 1864 and named after Ada Riggs, the daughter of one of Boise's founders, has evolved from its early days as a stop along the Oregon Trail to become one of the fastest-growing regions in the United States. As this growth continues, the county has implemented thoughtful lighting regulations that reflect its commitment to balancing modern development needs with preservation of the area's unique character.

The county's lighting regulations serve multiple purposes: enhancing public safety, maintaining community aesthetics, preserving the natural environment, and minimizing light pollution. These standards reflect Ada County's values of responsible development while respecting both urban and rural lifestyles within its boundaries.

Quick Reference Guide

• Purpose: Conserve energy, regulate glare, prevent nuisance, enhance nighttime enjoyment without decreasing safety, utility, or security
• Key Technical Requirements:
• Light fixtures with 260+ lumens require opaque tops to prevent up lighting
• Light fixtures with 1,000+ lumens require opaque tops and hidden bulbs
• Light fixtures with 1,800+ lumens require full cut-off shields
• Freestanding light fixtures limited to 25 feet or building height (whichever is less)
• Underground electrical feeds required for outdoor lighting
• Floodlights must be installed at no more than 45° from vertical
• Lighting Plan Required: For all developments needing master site plan approval

Applicability and Exemptions

When Lighting Regulations Apply

Ada County's lighting regulations apply to:

• Any proposed development requiring master site plan approval
• Any stationary outdoor lighting in common areas of planned unit developments or subdivisions
• Installation, change, upgrade, expansion, or enlargement of existing outdoor lighting

Exempt Lighting

The following lighting is exempt from Ada County's regulations:

• Light fixtures with a maximum output less than 260 lumens
• Lighting produced by direct combustion of fossil fuels (gas lamps, kerosene lanterns)
• Temporary holiday lighting used for 40 days or less per year

Prohibited Lighting Types

Ada County prohibits several types of lighting to maintain community standards:

• Mercury vapor lamp fixtures are not permitted
• Laser source lights or similar high-intensity lights when projected above horizontal
• Changing colors, moving lights, or searchlights for advertising purposes
• Lighting on tower structures that exceed district height limits (except as required by FAA)

Neon Considerations

It's important to note that neon illumination is prohibited in rural base districts of Ada County, though it may be permitted in other areas for appropriate signage applications.

Technical Requirements for Light Fixtures

Lumen Output Standards

Ada County has established clear standards based on the lumen output of fixtures:

• 260+ lumens: Fixtures must have an opaque top to prevent up lighting
• 1,000+ lumens: Fixtures must have an opaque top AND the bulb must not be visible
• 1,800+ lumens: Fixtures must have a "full cut-off shield" to prevent light pollution

Full Cut-Off Shield Definition

A full cut-off shield, in its installed position, will not allow any direct light above a horizontal plane, and no more than 5% of total light output may come from the zone from 15 degrees below horizontal to the horizontal plane.

Height Restrictions

The county regulates the height of lighting fixtures based on setback from property lines:

• Maximum height increases with greater setback from property lines
• Freestanding light fixtures cannot exceed 25 feet or the height of the principal permitted structure (whichever is less)
• Wall-mounted fixtures may extend to the full height of the structure

Installation Requirements

• Underground wiring: Electrical feeds to outdoor light fixtures must be underground, not overhead
• Floodlight positioning: Must prevent direct glare into roadways and minimize impact on neighboring properties
• Floodlight angle: Must be installed at no more than 45 degrees from vertical

Light Trespass and Property Boundaries

Ada County takes the impact of lighting on neighboring properties seriously:

• In commercial or industrial districts, the effective zone of light must not trespass onto abutting residential properties
• Lighting plans must document the photometric test report to ensure compliance
• Site lighting should be low intensity and utilize cut-off luminaires to minimize glare and impacts to surrounding residential areas

Up Lighting Restrictions

Up lighting is only allowed if the fixture and any light it emits are shielded from the sky by a roof overhang or similar structural shield.

Operational Requirements

Business and Display Lighting

• Display lighting must be turned off within 30 minutes after close of business
• Display lighting must remain off until sunrise or business opening the following day
• There are no time restrictions specifically for security lighting

Outdoor Recreation Facilities

• Illumination of outdoor amusement or recreation facilities is not permitted after 10:00 PM
• Exception: To conclude a scheduled event that was in progress before 10:00 PM
• All illumination must terminate no later than one hour after the conclusion of the event

Lighting Plan Requirements

When applying for development approval, a lighting plan must be submitted showing:

• Location, orientation, and height of all proposed exterior light fixtures
• Type and extent of shielding, including cut-off angles
• Type of illumination, including watts, luminous area, and photometric test report for each light source
• Compliance with all applicable standards in Chapter 4, Article H

The lighting plan must be approved by the Director or appropriate decision-making body. Alternative lighting plans may be approved when the overall design meets or exceeds the intent of the regulations.

Community-Specific Standards

Hidden Springs Community

The Hidden Springs community in Ada County has specific lighting guidelines:

• Small scale, intimate lighting for the Village Center
• Minimized lighting in rural residential areas to reduce light pollution
• Main intersections should be lit for safety purposes only
• Lighting should be functional and efficient while aligning with design themes
• Light pollution should be minimized throughout the development

Other Special Districts

• Development in the Avimor specific plan area must meet the requirements established in section B-13 of the Avimor specific plan
• Projects in Airport Influence Areas must comply with glare and height restrictions

Sign Illumination

Ada County has specific regulations for sign illumination:

• Building signs may have direct, internal, or neon illumination in many areas
• Property signs generally do not allow illumination
• Flashing or intermittent lighting is prohibited on most signage
• Signs using strobe lights or individual light bulbs exceeding 75 watts are prohibited
• Airport influence areas have special restrictions for sign lighting

Supporting Ada County's Lighting Vision

Bock Lighting, with roots dating back to 1918 in Northeast Ohio, shares Ada County's commitment to balancing development needs with community character preservation. We understand the unique challenges faced by rapidly growing communities like Ada County, where preserving historical integrity while accommodating modern growth is essential.

Our expertise in architectural lighting allows us to serve as a resource for Ada County property owners navigating these lighting regulations. We appreciate the county's thoughtful approach to lighting standards that enhance safety while minimizing light pollution and preserving the area's distinctive character.

As a company with experience in both historic preservation and modern lighting technologies, we recognize the importance of Ada County's balance between rural charm and urban functionality in its lighting approach. Our commitment to sustainable and responsible lighting practices aligns with the county's vision for thoughtful development.

Conclusion

Ada County's lighting regulations reflect its commitment to responsible growth that respects both the community's heritage and its future. These standards ensure that lighting enhances safety and functionality without creating nuisance or excessive light pollution.

Property owners planning lighting installations should consult with Ada County Development Services early in the planning process to ensure compliance with these regulations. By working together, residents and businesses can maintain Ada County's unique character while meeting practical lighting needs.

For the complete text of Ada County's lighting regulations, please refer to Chapter 4, Article H of the Ada County Code.