Morrisville Unified Development Ordinance - April 2019

Article 5: Development Standards Section 5.15. Exterior Lighting 5.15.3. Parking and Outdoor Lighting Light Levels

Table 5.15.3: Light Levels and Uniformity Ratios for High Pressure Sodium (HPS) and Metal Halide (MH) Lighting

Light Level (foot-candles) [1][2]

Average Light Level to Minimum Light Level Uniformity Ratio

Type of Lighting

Maximum

Average

Minimum

Anchor Tenant in a Major or Neighborhood Shopping Center

n/a

4.0

0.2

4:1

Loading Dock

n/a n/a

3.0 3.0 n/a n/a

0.2 0.2 0.2 0.2

4:1 4:1 5:1 4:1

Nonresidential Parking Lot

Vehicle Sales

20.0 20.0

Vehicular Canopy

Notes: n/a = not applicable [1] Maximum and average light levels shall be a horizontal measurement at grade or ground level of light level points on a ten-foot by ten-foot point-by-point layout grid in the overall lighted area. They shall be a not-to-exceed value measured or calculated using only the area of the site intended to receive illumination. [2] Measurements and calculations for a new system (after 100 hours of burn-in) shall be multiplied by a maintenance factor of not greater than 0.72 foot-candles for high pressure sodium lighting and 0.64 for metal halide lighting to determine compliance with the standards in this table. For example, if a maximum point measurement of 23 foot-candles was taken on a vehicle sales lot for a new metal halide lighting system, then 23 x 0.64 = 14.72 foot-candles. B. Light Levels and Uniformity Ratios for Light Emitting Diode (LED) Lighting Exterior light levels for Lighting Emitting Diode (LED) lighting shall comply with standards in Table 5.15.3.B: Light Levels and Uniformity Ratios for Light Emitting Diode (LED) Lighting, for the type of lighting. Table 5.15.3.B: Light Levels and Uniformity Ratios for Light Emitting Diode (LED) Lighting

Light Level (foot-candles) [1][2]

Average Light Level to Minimum Light Level Uniformity Ratio

Type of Lighting

Maximum

Average

Minimum

Anchor Tenant in a Major or Neighborhood Shopping Center

n/a

3.0

0.2

4:1

Loading Dock

n/a n/a

2.25 2.25

0.2 0.2 0.2 0.2

4:1 4:1 5:1 4:1

Nonresidential Parking Lot

Vehicle Sales

15.0 15.0

n/a n/a

Vehicular Canopy

Notes: n/a = not applicable [1] Maximum and average light levels shall be a horizontal measurement at grade or ground level of light level points on a ten-foot by ten-foot point-by-point layout grid in the overall lighted area. They shall be a not-to-exceed value measured or calculated using only the area of the site intended to receive illumination. [2] Measurements and calculations for a new system (after 100 hours of burn-in) shall be multiplied by a maintenance factor of not greater than 0.85 foot-candles to determine compliance with the standards in this table.

(Ord. No. 2016-001, 05/10/2016)

April 23, 2019

Morrisville, NC

Page 5-142

Unified Development Ordinance