Dobbins JLUS IMP Public Draft Light Pollution Study | Page 114

Notes to Table 4.1
Residential (lumens per residence)
total ( f ully shielded + u nshielded )
u nshielded component
See Section 16 for the definition of “residential.”
1. Spot and flood lamps must be aimed no higher than 45 degrees above straight down (half-
way between straight down and straight to the side) when the lamp is visible from any off-
site residential property or public roadway (Figure 4.1).

;


; 

; 
1
20,000
5,000
20,000
5,000
20,000
5,000
Notes to Table 4.2
1. Each residential single-family detached home or duplex is allowed up to 5,500 l umens of
unshielded lighting or the lighting provided in this Table based on the parcel's acreage,
whichever is larger, provided Table 4.1 allows the fixture(s) to be unshielded . Residential
spot or flood lamps are to be aimed no higher than 45 degrees above straight down (see
Note 1 to Table 4.1).
4.3. Lamp CCT Standard. All lamps, except lamps used for decorative lighting , must
conform to the CCT limits listed in Table 4.3.
: 
Table 4.3 ALLOWED LAMP CCT
Lighting Zone
LZ 1
LZ 2
Maximum CCT
3000K
3000K
Figure 4.1. Spot light aiming
2. The maximum amount of lighting in unshielded fixtures is limited in Section 4.2.
LZ 3
4300K 2
3. Seasonal decorations using typical unshielded low-wattage lamps or LEDs shall be
permitted from Thanksgiving through January 15; such lighting is not subject to the
shielding or total outdoor light output standards of this code. 4.4. Effective Shielding Standard. All light fixtures that are required to be fully shielded shall
be installed and maintained in such a manner that the shielding is effective as described in
the definition for fully shielded fixtures.
4. Examples of lamp types of 2,000 and 1,000 lumens and below (The acceptability of a
particular light is determined by initial lumen output, not wattage; values listed are
approximate; check manufacturer’s specifications). 4.5. “House Side” Shielding Standard. Beyond the shielding requirements of Section 4.1,
any privately or publicly owned outdoor light fixture with a lamp of initial output over
10,000 lumens located within 50 feet of any residential (including multi-family residential)
property or public right-of-way shall utilize an internal or external “house-side” shield, with
the light fixture and shield oriented to minimize light trespass over the adjacent property
or right-of-way line (Figure 4.5). The surface of any external shield must have a black or
bronze finish on the side facing the lamp to minimize reflection.
Lamp Type
Standard incandescent and less
Tungsten-halogen (quartz) and less
Fluorescent and less
Compact Fluorescent and less
Metal Halide
High-Pressure Sodium
2000 lumens
100 watt
100 watt
25 watt
26 watt
40 watt
N/A
1000 lumens
60 watt
60 watt
15 watt
13 watt
N/A
N/A
4.2. Total Outdoor Light Output Standards. Total outdoor light output shall not exceed
the limits set forth in Table 4.2. (The values in this table are upper limits and not design
goals; design goals should be the lowest levels that meet the requirements of the task.)

Table 4.2 MAXIMUM TOTAL OUTDOOR LIGHT OUTPUT STANDARDS
Land Use and Fixture Shielding
Commercial, Industrial, Multi--family residential
( lumens per net acre )
total ( fully shielded + unshielded )
u nshielded component
Page A- 46
Lighting Zone
No Shield
Notes
LZ 1 LZ 2 LZ 3
50,000
5,000 100,000
10,000 150,000
10,000


Internal Shield
External Shield
Figure 4.5. House-side shield configurations
2
To decrease potential disruption of human circadian rhythms and sky glow, a CCT limit of 3000K should be
considered in all Lighting Zones.
Appendix A:
White Paper – Communities Addressing Light Pollution that Affect Nighttime Military Training