Log in
LEED v4
Neighborhood Development Plan
Green infrastructure & buildings
Light pollution reduction

LEED CREDIT

ND-Plan-v4 GIBc17: Light Pollution Reduction 1 point

See all forum discussions about this credit »

SPECIAL REPORT

LEEDuser expert

Bill Swanson

PE, LEED AP BD+C

Feyen Zylstra
Sr. Electrical Engineer

SPECIAL REPORT

LEEDuser’s viewpoint

Explore this LEED credit

Post your questions on this credit in the forum, and click on the credit language tab to review to the LEED requirements.

Credit language

USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Requirements

Meet the Light Pollution Reduction requirements for the following:

  1. One option in Exterior Lighting for Residential Areas
  2. Exterior Lighting for Circulation Network
  3. Uplight and light trespass requirements in Exterior Lighting for All Other Areas
  4. Covenants, Conditions, and Restrictions.
Divide the project into model lighting ordinance (MLO) lighting zones LZ0 to LZ4 based on site-specific characteristics using the definitions of lighting zones provided in the Illuminating Engineering Society and International Dark Sky Association (IES/IDA) MLO User Guide. Meet the requirements below for each lighting zone within the project.
Exterior lighting for residential areas
Meet either Option 1 or Option 2 for all exterior lighting in new residential construction and residential buildings undergoing major renovations. Existing residential construction is exempt. Projects may use different options for uplight and light trespass.
Option 1. BUG rating method
Each fixture must have a backlight-uplight-glare (BUG) rating (as defined in IES TM-15-11, Addendum A) of no more than B2-U2-G2.
OR
Option 2. Calculation method
Meet the requirements of Option 2 in Exterior Lighting for All Other Areas, below.
Exterior lighting for circulation network
For any portions of the circulation network not governed by national, state, or other superseding regulations, do not install street lighting unless conditions warrant the need for street lighting. New and existing street lighting luminaires must not emit any light above 90 degrees (horizontal), based on the photometric characteristics of each luminaire when mounted in the same orientation and tilt as specified in the project design or as currently installed. Exception for ornamental luminaires: Using the lowest MLO lighting zone for immediately adjacent properties, meet the requirements of the IES/IDA MLO, Table H.

AND

Exterior lighting for all other areas
Use either the BUG method (Option 1) or the calculation method (Option 2) to meet uplight and light trespass requirements. Projects may use different options for uplight and light trespass.
Uplight
Option 1. BUG rating method
Do not exceed the following luminaire uplight ratings, based on the specific light source installed in the luminaire, as defined in IES TM-15-11, Addendum A.
Table 1. maximum uplight ratings for luminaires, by lighting zone

MLO lighting zone

Luminaire uplight rating

LZ0

U0

LZ1

U1

LZ2

U2

LZ3

U3

LZ4

U4

OR
Option 2. calculation method
Do not exceed the following maximum percentages of total lumens emitted above horizontal.
Table 2. Maximum percentage of lumens above horizontal, by lighting zone

MLO lighting zone

Maximum allowed percentage of total luminaire lumens emitted above horizontal

LZ0

0%

LZ1

0%

LZ2

1.5%

LZ3

3%

LZ4

6%

Light trespass
Option 1. BUG Rating Method
Do not exceed the following luminaire backlight and glare ratings (based on the specific light source installed in the luminaire) as defined in IES TM-15-11, Addendum A, based on the mounting location and distance from the lighting boundary.
Table 3. Maximum backlight and glare ratings

 

MLO lighting zone

Luminaire mounting

LZ0

LZ1

LZ2

LZ3

LZ4

 

Allowed backlight ratings

> 2 mounting heights from lighting boundary

B1

B3

B4

B5

B5

1 to 2 mounting heights from lighting boundary and properly oriented

B1

B2

B3

B4

B4

0.5 to 1 mounting height to lighting boundary and properly oriented

B0

B1

B2

B3

B3

< 0.5 mounting height to lighting boundary and properly oriented

B0

B0

B0

B1

B2

 

Allowed glare ratings

Building-mounted > 2 mounting heights from any lighting boundary

G0

G1

G2

G3

G4

Building-mounted 1–2 mounting heights from any lighting boundary

G0

G0

G1

G1

G2

Building-mounted 0.5 to 1 mounting heights from any lighting boundary

G0

G0

G0

G1

G1

Building-mounted < 0.5 mounting heights from any lighting boundary

G0

G0

G0

G0

G1

All other luminaires

G0

G1

G2

G3

G4

A lighting boundary (or boundaries) is defined as the perimeter of each lighting zone within the project boundary. A lighting boundary can be modified under the following conditions:
  • When the property line is adjacent to a public area that is a walkway, bikeway, plaza, or parking lot, the lighting boundary may be moved to 5 feet (1.5 meters) beyond the property line;
  • When the property line is adjacent to a public street, alley, or transit corridor, the lighting boundary may be moved to the center line of that street, alley, or corridor;
  • When there are additional properties owned by the same entity that are contiguous to the property, or properties, that the LEED project is within and have the same or higher MLO lighting zone designation as the LEED project, the lighting boundary may be expanded to include those properties.
Orient all luminaires less than two mounting heights from the lighting boundary such that the backlight points toward the nearest lighting boundary line. Building-mounted luminaires with the backlight oriented toward the building are exempt from the backlight rating requirement
Option 2. calculation method
Do not exceed the following vertical illuminances at the lighting boundary of each lighting zone in the project (use the definition of lighting boundary in Option 1). Calculation points may be no more than 5 feet (1.5 meters) apart. Vertical illuminances must be calculated on vertical planes running parallel to the lighting boundary, with the normal to each plane oriented toward the property and perpendicular to the lighting boundary, extending from grade level to 33 feet (10 meters) above the height of the highest luminaire.
Table 4. maximum vertical illuminance at lighting boundary, by lighting zone

MLO lighting zone

Vertical illuminance

LZ0

0.05 fc (0.5 lux)

LZ1

0.05 fc (0.5 lux)

LZ2

0.10 fc (1 lux)

LZ3

0.20 fc (2 lux)

LZ4

0.60 fc (6 lux)

FC = footcandle
Exemptions from uplight and light trespass requirements
The following exterior lighting is exempt from the requirements, provided it is controlled separately from the nonexempt lighting:
  • specialized signal, directional, and marker lighting for transportation;
  • internally illuminated signage;
  • lighting that is used solely for façade and landscape lighting in MLO lighting zones 3 and 4 and is automatically turned off from midnight until 6 a.m.;
  • lighting that is integral to other equipment or instrumentation that has been installed by the equipment or instrumentation manufacturer;
  • lighting for theatrical purposes for stage, film, and video performances;
  • street lighting;
  • hospital emergency departments, including associated helipads; and
  • lighting for the national flag in MLO lighting zones 2, 3, or 4
Covenants, conditions, and restrictions
Establish covenants, conditions, and restrictions (CC&R) or other binding documents that require continued adherence to the above requirements. See all forum discussions about this credit »

What does it cost?

Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Learn more about The Cost of LEED v4 »

Addenda

10/1/2014Updated: 2/14/2015
Rating System Correction
Description of change:
Exterior lighting for residential areas: add sentence to end of paragraph (before Option 1) that reads:
"Projects may use different options for uplight and light trespass."
Campus Applicable
Yes
Internationally Applicable:
Yes
See all forum discussions about this credit »

Documentation toolkit

The motherlode of cheat sheets

LEEDuser’s Documentation Toolkit is loaded with calculators to help assess credit compliance, tracking spreadsheets for materials, sample templates to help guide your narratives and LEED Online submissions, and examples of actual submissions from certified LEED projects for you to check your work against. To get your plaque, start with the right toolkit.

LEEDuser expert

Bill Swanson

PE, LEED AP BD+C

Feyen Zylstra
Sr. Electrical Engineer

USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Requirements

Meet the Light Pollution Reduction requirements for the following:

  1. One option in Exterior Lighting for Residential Areas
  2. Exterior Lighting for Circulation Network
  3. Uplight and light trespass requirements in Exterior Lighting for All Other Areas
  4. Covenants, Conditions, and Restrictions.
Divide the project into model lighting ordinance (MLO) lighting zones LZ0 to LZ4 based on site-specific characteristics using the definitions of lighting zones provided in the Illuminating Engineering Society and International Dark Sky Association (IES/IDA) MLO User Guide. Meet the requirements below for each lighting zone within the project.
Exterior lighting for residential areas
Meet either Option 1 or Option 2 for all exterior lighting in new residential construction and residential buildings undergoing major renovations. Existing residential construction is exempt. Projects may use different options for uplight and light trespass.
Option 1. BUG rating method
Each fixture must have a backlight-uplight-glare (BUG) rating (as defined in IES TM-15-11, Addendum A) of no more than B2-U2-G2.
OR
Option 2. Calculation method
Meet the requirements of Option 2 in Exterior Lighting for All Other Areas, below.
Exterior lighting for circulation network
For any portions of the circulation network not governed by national, state, or other superseding regulations, do not install street lighting unless conditions warrant the need for street lighting. New and existing street lighting luminaires must not emit any light above 90 degrees (horizontal), based on the photometric characteristics of each luminaire when mounted in the same orientation and tilt as specified in the project design or as currently installed. Exception for ornamental luminaires: Using the lowest MLO lighting zone for immediately adjacent properties, meet the requirements of the IES/IDA MLO, Table H.

AND

Exterior lighting for all other areas
Use either the BUG method (Option 1) or the calculation method (Option 2) to meet uplight and light trespass requirements. Projects may use different options for uplight and light trespass.
Uplight
Option 1. BUG rating method
Do not exceed the following luminaire uplight ratings, based on the specific light source installed in the luminaire, as defined in IES TM-15-11, Addendum A.
Table 1. maximum uplight ratings for luminaires, by lighting zone

MLO lighting zone

Luminaire uplight rating

LZ0

U0

LZ1

U1

LZ2

U2

LZ3

U3

LZ4

U4

OR
Option 2. calculation method
Do not exceed the following maximum percentages of total lumens emitted above horizontal.
Table 2. Maximum percentage of lumens above horizontal, by lighting zone

MLO lighting zone

Maximum allowed percentage of total luminaire lumens emitted above horizontal

LZ0

0%

LZ1

0%

LZ2

1.5%

LZ3

3%

LZ4

6%

Light trespass
Option 1. BUG Rating Method
Do not exceed the following luminaire backlight and glare ratings (based on the specific light source installed in the luminaire) as defined in IES TM-15-11, Addendum A, based on the mounting location and distance from the lighting boundary.
Table 3. Maximum backlight and glare ratings

 

MLO lighting zone

Luminaire mounting

LZ0

LZ1

LZ2

LZ3

LZ4

 

Allowed backlight ratings

> 2 mounting heights from lighting boundary

B1

B3

B4

B5

B5

1 to 2 mounting heights from lighting boundary and properly oriented

B1

B2

B3

B4

B4

0.5 to 1 mounting height to lighting boundary and properly oriented

B0

B1

B2

B3

B3

< 0.5 mounting height to lighting boundary and properly oriented

B0

B0

B0

B1

B2

 

Allowed glare ratings

Building-mounted > 2 mounting heights from any lighting boundary

G0

G1

G2

G3

G4

Building-mounted 1–2 mounting heights from any lighting boundary

G0

G0

G1

G1

G2

Building-mounted 0.5 to 1 mounting heights from any lighting boundary

G0

G0

G0

G1

G1

Building-mounted < 0.5 mounting heights from any lighting boundary

G0

G0

G0

G0

G1

All other luminaires

G0

G1

G2

G3

G4

A lighting boundary (or boundaries) is defined as the perimeter of each lighting zone within the project boundary. A lighting boundary can be modified under the following conditions:
  • When the property line is adjacent to a public area that is a walkway, bikeway, plaza, or parking lot, the lighting boundary may be moved to 5 feet (1.5 meters) beyond the property line;
  • When the property line is adjacent to a public street, alley, or transit corridor, the lighting boundary may be moved to the center line of that street, alley, or corridor;
  • When there are additional properties owned by the same entity that are contiguous to the property, or properties, that the LEED project is within and have the same or higher MLO lighting zone designation as the LEED project, the lighting boundary may be expanded to include those properties.
Orient all luminaires less than two mounting heights from the lighting boundary such that the backlight points toward the nearest lighting boundary line. Building-mounted luminaires with the backlight oriented toward the building are exempt from the backlight rating requirement
Option 2. calculation method
Do not exceed the following vertical illuminances at the lighting boundary of each lighting zone in the project (use the definition of lighting boundary in Option 1). Calculation points may be no more than 5 feet (1.5 meters) apart. Vertical illuminances must be calculated on vertical planes running parallel to the lighting boundary, with the normal to each plane oriented toward the property and perpendicular to the lighting boundary, extending from grade level to 33 feet (10 meters) above the height of the highest luminaire.
Table 4. maximum vertical illuminance at lighting boundary, by lighting zone

MLO lighting zone

Vertical illuminance

LZ0

0.05 fc (0.5 lux)

LZ1

0.05 fc (0.5 lux)

LZ2

0.10 fc (1 lux)

LZ3

0.20 fc (2 lux)

LZ4

0.60 fc (6 lux)

FC = footcandle
Exemptions from uplight and light trespass requirements
The following exterior lighting is exempt from the requirements, provided it is controlled separately from the nonexempt lighting:
  • specialized signal, directional, and marker lighting for transportation;
  • internally illuminated signage;
  • lighting that is used solely for façade and landscape lighting in MLO lighting zones 3 and 4 and is automatically turned off from midnight until 6 a.m.;
  • lighting that is integral to other equipment or instrumentation that has been installed by the equipment or instrumentation manufacturer;
  • lighting for theatrical purposes for stage, film, and video performances;
  • street lighting;
  • hospital emergency departments, including associated helipads; and
  • lighting for the national flag in MLO lighting zones 2, 3, or 4
Covenants, conditions, and restrictions
Establish covenants, conditions, and restrictions (CC&R) or other binding documents that require continued adherence to the above requirements.

LEEDuser expert

Bill Swanson

PE, LEED AP BD+C

Feyen Zylstra
Sr. Electrical Engineer

See all LEEDuser forum discussions about this credit » Unsubscribe from discussions about ND-Plan-v4 GIBc17