Lighting Regulations in San Diego County, California: Preserving Dark Skies While Ensuring Safety and Function

Introduction: Why San Diego County Regulates Lighting

San Diego County's unique geographic setting—bordered by the Pacific Ocean and desert landscapes—combined with its rich historical legacy has shaped its approach to lighting regulations. Since the establishment of the Palomar Observatory in 1928 and the Mount Laguna Observatory in 1968, the county has been committed to reducing light pollution to protect these valuable scientific resources.

The county's regulations reflect a careful balance between preserving its dark skies, ensuring public safety, and respecting the architectural heritage that dates back to Spanish colonial times. These regulations have evolved as San Diego County has grown from its early days as a mission settlement to a modern metropolitan area of over 3 million residents.

Quick Reference Guide: Essential San Diego County Lighting Requirements

Key lighting zones:

• Zone A: Most restrictive - areas surrounding observatories
• Zone B: Moderately restrictive
• Zone C: Least restrictive - urban areas

Maximum allowable light:

• 50,000 lumens per gross acre (5,000 lumens minimum for any property)
• Non-fully shielded lighting limited to 10% of maximum allowed lumens

Color temperature requirements:

• CCT ≤ 3,000K in Zone C
• Low pressure sodium or narrow spectrum amber LED in Zones A and B

Light trespass limits:

• ≤ 2.0 vertical footcandles at property lines

Required illumination levels for specific facilities:

• Dance facilities: Minimum 1 foot-candle illumination
• Body art workstations: Minimum 50 foot-candles at procedure site
• Massage rooms: Minimum 5 foot-candles at any point in the room
• Bathhouses: 10-12 foot-candles measured 30 inches above floor

Understanding San Diego County's Three Lighting Zones

San Diego County has established three distinct geographic lighting zones to balance dark sky preservation with urban development needs.

Zone A: Observatory Protection Areas

Purpose: Provides the highest level of protection for areas surrounding the Palomar and Mount Laguna observatories.

Key requirements:

• Fully shielded luminaires required for most applications
• Low pressure sodium or narrow spectrum amber LED lighting preferred
• Prohibited: Unshielded decorative lighting
• Lighting must be extinguished between 11:00 p.m. and sunrise

Zone B: Rural and Semi-Rural Areas

Purpose: Provides moderate protection for transitional areas.

Key requirements:

• Fully shielded luminaires required for lights exceeding 4,050 lumens
• Motion-activated luminaires allowed up to 2,000 lumens unshielded
• Entrance luminaires permitted up to 2,000 lumens unshielded
• Most lighting must be turned off between 11:00 p.m. and sunrise

Zone C: Urban Areas

Purpose: Provides basic dark sky protection while allowing more flexibility in developed areas.

Key requirements:

• Fully shielded luminaires required for lights exceeding 1,000 lumens
• CCT ≤ 3,000K for all outdoor lighting
• Color rendering considerations for commercial and safety applications

Lighting Classifications and Their Requirements

San Diego County divides lighting into three classes based on their function, with different requirements for each.

Class I: Color-Critical Lighting

Definition: Outdoor lighting for sales areas, eating areas, vehicle fueling areas, and other applications where color rendition is important.

Requirements:

• Fully shielded fixtures required in all zones
• Must be turned off after business hours (with exceptions)
• Must meet zone-specific color temperature requirements

Class II: Safety and Security Lighting

Definition: Outdoor lighting for walkways, roadways, parking lots, equipment yards, and entrance lighting.

Requirements:

• Fully shielded fixtures required for luminaires exceeding zone thresholds
• May remain on overnight when needed for safety
• Motion sensors required for certain applications

Class III: Decorative Lighting

Definition: Outdoor lighting used for architectural illumination, monument lighting, flags, and landscape lighting.

Requirements:

• Most restrictive category in terms of hours of operation
• Limited use in Zone A
• Must be extinguished after business hours (with exceptions)

Special Applications and Requirements

Recreational and Sports Lighting

Sport fields and recreational facilities have specific exemptions and requirements:

• Must follow IES illuminance and uniformity guidelines
• In Zone C, correlated color temperature must be ≤ 4,200K
• Must use internal or external shielding to minimize uplight
• Lights must be extinguished by 10:00 p.m. or one hour after end of play
• Title 24-compliant timing devices required

Signage Requirements

Different rules apply to on-premises and off-premises signs:

• On-premises signs: Must be shielded where feasible and focused to minimize light spill
• Off-premises signs: Must be aimed downwards and fully shielded
• All signs must have a luminance of ≤ 100 candelas per square meter between sunset and sunrise
• Maximum illuminated surface area: 200 square feet per sign

Cannabis Facilities

Medical Cannabis Collective Facilities, Commercial Cannabis Microbusinesses, and Commercial Cannabis Retailers have specific lighting requirements:

• Must comply with the County Light Pollution Code
• Lighting must provide sufficient foot-candles and color rendition to allow identification of individuals at a distance of at least 40 feet
• Exterior landscaping must be free of places where a person could conceal themselves

What Property Owners Should Know

Permit Requirements and Documentation

When applying for permits involving outdoor lighting, property owners must submit:

• A map showing the property location
• Plans indicating the location of each type of outdoor luminaire
• Detailed specifications for each outdoor luminaire
• Photometric studies where required

Compliance Timelines

• New installations must comply immediately
• Zone C properties have a 10-year compliance timeline from the date of ordinance adoption
• Special provisions may apply to pre-existing installations

Common Exemptions

Not all lighting is subject to these regulations. Exemptions include:

• Holiday decorations (limited to 60 days per year and off between 11:00 p.m. and sunrise)
• Fossil fuel lighting (kerosene lanterns, gas lamps)
• Flag lighting (with specific restrictions)
• Life-safety luminaires that only operate during power failures

Supporting San Diego County's Lighting Vision

Bock Lighting, with roots dating back to 1918, understands the importance of balancing modern lighting needs with the preservation of dark skies and historical character. As a manufacturer with experience in diverse communities, we appreciate San Diego County's efforts to protect its astronomical observatories while maintaining safe and functional lighting for residents and businesses.

Our team recognizes the unique challenges San Diego County faces with its varied landscapes—from coastal communities to desert regions—and the need for lighting solutions that respect these diverse environments. We're committed to helping communities understand and implement lighting regulations that protect their unique character.

Bock Lighting serves as an educational resource for property owners navigating lighting regulations, offering expertise in solutions that maintain compliance while enhancing architectural character. Our understanding of regional architectural styles, from Spanish Colonial to Craftsman to Contemporary, allows us to support lighting designs that complement San Diego County's rich architectural heritage.

Conclusion

San Diego County's lighting regulations reflect a thoughtful approach to balancing multiple community needs: protecting world-class observatories, preserving dark skies, ensuring public safety, and respecting the county's rich architectural heritage. By understanding these regulations and planning accordingly, property owners can contribute to the county's lighting vision while creating beautiful, functional spaces.

Whether you're installing new exterior lighting or updating existing fixtures, compliance with these regulations helps preserve San Diego County's unique character and natural resources for future generations. The careful balance of light levels, shielding requirements, and color temperature specifications ensures that artificial lighting serves its purpose without unnecessary light pollution.