Morrisville Unified Development Ordinance - October 2019

Article 5: Development Standards Section 5.15. Exterior Lighting 5.15.4. Fixture Requirements

The following fixtures shall not be permitted:

a. Cutoff where full cutoff is required; and

b. Other fixtures deemed architecturally non-compatible by the Planning Director.

The color and style of the fixture shall complement the architectural character of the building.

The light pole cannot be greater than 35 feet in height above the ground level at its base. Raised foundations are permissible where appropriate for parking. Light levels shall comply with the standards in Section 5.15.3, Parking and Outdoor Lighting Light Levels.

The maximum light level shall not exceed one-half the horizontal maintained foot- candles of light trespass at any residential property line. Service connections for all freestanding fixtures shall be underground.

D. Covered Parking Garage parking facilities shall be lighted to IESNA recommendations outlined in Table 5.15.4.D: Light Levels and Uniformity Ratios for Covered Parking, for the type of lighting.

Figure 5.15.4.D: Anchor Tenant Covered Parking.

Table 5.15.4.D: Light Levels and Uniformity Ratios for Covered Parking

Minimum Horizontal Light Level [1]

Maximum Horizontal Light Level to Minimum

Minimum Vertical Light Level [4]

Type of Lighting

Horizontal Light Level Uniformity Ratio [3]

Lux

Foot-candle [2]

Lux

Foot-candle [2]

Basic [5]

10 20 10

1 2 1

10:1 10:1 10:1 10:1 10:1 10:1

5

0.5

Day [7]

10

1

Ramps [6]

Night

5

0.5 25 0.5

Day

500

50

250

Entrance Areas [8] Stairways

Night

10 20

1 2

5

10

1

Notes: [1] Measured on the parking surface, without any shadowing effect from parked vehicles or columns. For preliminary design, an average value of 50 horizontal lux (5 horizontal foot-candles) for basic illuminance (and equivalent for other conditions) may be calculated. [2] Rounded conversion of lux to foot-candles. [3] The highest horizontal illuminance area, divided by the lowest horizontal illuminance area, shall not be greater than the ratio shown. [4] Measured at 1.5 meters (5.0 feet) above parking surface at the point of lowest horizontal illuminance, excluding facing outward along boundaries. [5] For typical conditions. While these values are intended to address personal security issues, some retailers may increase them to further offset perceived concerns. Top levels of garages open to the sky shall not exceed 0.5 foot-candles minimum with a maximum to minimum uniformity ratio of 15:1 horizontal and 0.25 foot-candle minimum vertical illuminance (source IESNA 9 th edition handbook). The mounting height on the top level of a garage shall not be greater than 22 feet above the parking deck top floor, including raised foundations, and the light fixture classification shall be full cutoff. [6] Applies to clearway ramps (no adjacent parking) but not to sloping floor designs. [7] Daylight may be considered in the design calculation. [8] A high illuminance level for about the first 20 meters (66 feet) inside the structure is needed to effect a transition from bright daylight to a lower internal level.

Morrisville, NC

October 1, 2019

Unified Development Ordinance

Page 5-153