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LEED BD+C: New Construction | v3 - LEED 2009

Light pollution reduction

SSpc7 | Possible 1 point

Intent

Pilot Credit Closed

This pilot credit is closed to new registrations

To increase night sky access, improve nighttime visibility, and reduce the consequences of development for wildlife and people.

Requirements

Meet uplight and light trespass requirements, using either the backlight-uplight-glare (BUG) method (Option 1) or the calculation method (Option 2). Projects may use different options for uplight and light trespass.

Meet these requirements for all exterior luminaires located inside the project boundary (except those listed under “Exemptions”), based on the following:

  • the photometric characteristics of each luminaire when mounted in the same orientation and tilt as specified in the project design; and
  • the lighting zone of the project property (at the time construction begins). Classify the project under one lighting zone using the lighting zones definitions provided in the Illuminating Engineering Society and International Dark Sky Association (IES/IDA) Model Lighting Ordinance (MLO) User Guide.

Additionally, meet the internally illuminated signage requirement.

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

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 percentages of total lumens emitted above horizontal.

Table 2. maximum percentage of total lumens emitted 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%

AND
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

The lighting boundary is located at the property lines of the property, or properties, that the LEED project occupies. The 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.

OR
Option 2. calculation method

Do not exceed the following vertical illuminances at the lighting boundary (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)

AND

Internally illuminated exterior signage

Do not exceed a luminance of 200 cd/m2 (nits) during nighttime hours and 2000 cd/m2 (nits) during daytime hours.

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;
  • 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 for theatrical purposes for stage, film, and video performances;
  • government-mandated roadway lighting;
  • hospital emergency departments, including associated helipads;
  • lighting for the national flag in MLO lighting zones 2, 3, or 4; and
  • internally illuminated signage.
Credit specific
Building Design & Construction

Exterior Lighting – provide the following:

  • A site plan showing all sign locations and exterior light fixtures with designations and an associated fixture schedule with brief descriptions including lamp information for all fixtures
  • A description with drawings and/or images of the site and all immediately adjacent properties, documenting a lighting zone for each of these. Any lighting zone
    4 designations should include a document from the local zoning authority showing that they have authorized that zone designation for that site.
  • A list of all exempt exterior luminaires and which exemption they qualify under.
  • Signage: Narrative and drawings describing the luminance levels of the signs during hours of darkness and hours of daylight. Daylight hours are between 30 minutes after sunrise and 30 minutes before sunset. Nighttime hours are between 30 minutes after sunset and 30 minutes before sunrise.
    • Uplight
      Option 1 BUG Rating Method:

      • The lighting zone designation used for this option
      • A lighting schedule documenting the three-dimensional orientation (plan/ elevation) of each non-exempt exterior fixture and it’s U-Rating in that orientation (identical luminaires in the same orientation may be grouped).

      Option 2 Calculation Method:

      • The lighting zone designation used for this option
      • A spreadsheet showing the following for each non-exempt luminaire (including summations where appropriate): (identical luminaires in the same orientation may be grouped)
        1. Catalog #
        2. Quantity of this luminaire
        3. The three dimensional orientation of the luminaire (plan/ elevation)
        4. The lumens emitted by the luminaire in that orientation
        5. The lumens emitted by the luminaire in that orientation above the horizon
      • A summation calculation showing compliance based on the data presented above.

      Light Trespass
      Option 1 BUG Rating Method:

      • The lighting zone designation used for this option
      • Where appropriate, a narrative justifying extending the lighting boundary line past the property line in accordance with the credit requirements.
      • a spreadsheet showing the following for each non-exempt luminaire: (identical luminaires in the same orientation may be grouped)
        1. Catalog #
        2. The three dimensional orientation of the luminaire (plan/ elevation)
        3. The orientation of the luminaire relative to the nearest lighting boundary line
        4. The backlight and glare ratings of the luminaire in the defined position
        5. An statement of compliance

      Option 2 Calculation Method:
      A point-by-point calculation showing initial vertical illuminances. Each vertical plane shall include:

      • The maximum vertical illuminance encountered
      • The lighting zone for this plane
      • A statement of compliance
      • Multitenant Complex Projects:
        Include a narrative that describes:

        • How the safety/security issues, comfort, and economic activity were addressed and enhanced,
        • The shared exterior lighting amenities,
        • How light pollution and energy consumption was minimized, and
        • How specific projects fit into the overall design.
        Existing Buildings: Operations & Maintenance

        Interior Lighting- provide the following:

        • Narrative and drawings showing control locations, describing the lighting controls used on the interior lighting, the sequence of operation, and how these controls comply with this credit and section 9 of the ANSI/ASHRAE/IES Standard 90.1-2010.

        Exterior Lighting

        Option 1:

        • A luminaire schedule identifying those luminaires where the sum of the mean lamp lumens exceeds 2,500
        • A photometric report of those luminaires demonstrating that no light is emitted above 90 degrees from straight down in their final installed position(s).

        Option 2:

        • Provide proof that the project complies with NC, CS, Schools, Retail, Healthcare above.

        Option 3:

        • A plan showing the location of the measurement points used to measure the night illumination levels.
        • A description of the measurement results.
Additional questions
  1. Were you able to understand and comply with the credit language as written?
  2. Were there barriers to implementing the strategies used under this credit?
  3. Do the criteria associated with quality exterior lighting align with your project’s productivity, safety, and quality needs?
Changes:
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