A. Purpose
The intent of the sight lighting standards is to provide a level of illumination necessary for adequate, safe, and efficient movement of vehicles and persons without affecting neighboring properties. Further, the level of illumination may vary according to the type of use on a lot. Prior to the approval of a Building Permit, Occupancy Permit, Property Maintenance, or Certificate of Zoning Compliance, a plan demonstrating compliance with the following exterior lighting standards will be submitted and approved by the City Planner for non-residential uses.
1. Lighting parking, loading and service areas must all be consistent in color, size, height and design.
2. When field measurements of light readings are made, they are to be taken with a light meter at grade.
3. All commercial developments with 10 or more parking spaces are required to lighting for the entire area used for vehicles, exterior doorways, and access doorways.
4. Apartments, townhomes, attached single-family, patio homes or residential development accessed by private streets with evenly distributed parking with clusters of five exterior spaces or less shall:
a. Illuminate all private streets or main traffic circulation aisles in compliance with this Section.
b. Illuminate secondary areas for vehicle use, such as driveways or and motor courts by post mounted or wall mounted fixtures in keeping with the residential character of the area.
c. All multi-family residential developments with clusters of six exterior parking spaces or more are to be illuminated in compliance with the required standard listed above for commercial developments.
B. Applicability
All non-residential developments are required to provide exterior lighting for all exterior doorways, pedestrian pathways, and parking and loading/service areas.
C. Minimum Site Lighting Criteria
All exterior lighting shall meet the following minimum standards and be demonstrated on all plan submittals:
1. 0.5 Foot-candles Average Maintained: Measured at grade in all parking and loading areas and pedestrian pathways. Actual site measurement compliance shall not drop below a minimum of 0.3 foot-candles at any one location. For design purposes, the light loss factor (LLF) as defined in Article 11 shall be calculated at: (Ord. 17-16)
a. 0.7 LLF for Incandescent, Metal Halide, and Mercury Vapor lamp sources.
b. 0.8 LLF for Fluorescent and Sodium lamp sources.
c. 0.9 LLF for Light Emitting Diode (LED) lamp sources.
2. Lighting Uniformity Shall Not Exceed:
a. 10:1 Maximum to minimum light levels.
b. 4:1 Average to minimum light levels.
3. Pole Mounted Luminaire Overall Height Limitations: Height shall be measured from finished grade to top of fixture unless otherwise limited.
Office, Commercial & Inst. 25 feet maximum
Mixed Use 30 feet maximum
4. The color temperature of exterior illumination shall appear as natural or neutral ranging from a minimum of 2,200K (high pressure sodium) to a maximum of 5,400K (metal halide) as measured in Degrees Kelvin.
D. Light Trespass Criteria
Light originating on a site shall not be permitted beyond the site to exceed the following values when measured at grade 10 feet beyond the property line for the following adjacent properties:
Single-Family 0.3 foot-candles
Multi-Family 0.5 foot-candles
Office, Commercial & Inst. 1.0 foot-candles
Mixed Use 1.0 foot-candles
Industrial Warehouse 1.5 foot-candles
Highway Commercial 1.5 foot-candles
Outdoor Sports Facilities will be reviewed for compliance with regard to the intent of these exterior lighting standards to minimize the impact of light trespass and glare on all surrounding properties and public rights-of-way.
Service station and service station/mini-mart canopy lighting and outdoor display area lighting used in conjunction with a vehicle sale, rental and ancillary service establishment must not exceed an average lighting level of 25 foot-candles as measured horizontally at grade.
E. Glare Control Criteria
1. All exterior lighting used to light parking lots, loading/service areas, and pedestrian pathways shall be "total full cutoff type" as defined by the Illuminating Engineering Society of North America's (IESNA) latest standard. The four IESNA classifications are defined as follows (IESNA 2000):
a. Full cutoff—The luminous intensity (in candelas) at or above an angle of 90° above nadir is zero, and the luminous intensity (in candelas) at or above a vertical angle of 80° above nadir does not numerically exceed 10% of the luminous flux (in lumens) of the lamp or lamps in the luminaire.
b. Cutoff—The luminous intensity (in candelas) at or above an angle of 90° above nadir does not numerically exceed 2.5% of the luminous flux (in lumens) of the lamp or lamps in the luminaire, and the luminous intensity (in candelas) at or above a vertical angle of 80° above nadir does not numerically exceed 10% of the luminous flux (in lumens) of the lamp or lamps in the luminaire.
c. Semi-cutoff—The luminous intensity (in candelas) at or above an angle of 90° above nadir does not numerically exceed 5% of the luminous flux (in lumens) of the lamp or lamps in the luminaire, and the luminous intensity (in candelas) at or above a vertical angle of 80° above nadir does not numerically exceed 20% of the luminous flux (in lumens) of the lamp or lamps in the luminaire.
d. Non-cutoff—There is no candela limitation in the zone above maximum candela.
2. All other exterior lighting, including but not limited to doorways, architectural, accent, landscape, signage, decorative, security, floodlighting, or area lighting shall be "total cutoff type" or no portion of the lamp, reflector, lens, or refracting system may extend beyond the housing or shield so as to create or allow glare to be visible from off site, except the following:
a. Lighting required by the Building Code for emergency egress when operating in emergency conditions; or
b. Light sources which do not exceed 2300 initial lumens or 4000 main beam candlepower.
F. Lighting Plan Submittal Criteria: See Article 5 for submittal requirements.