Our project is located at the instersection of two Class 1 Pedestrian Streets in Downtown Seattle. The neighborhood is zoned Downtown Mixed Commercial, allowing for a variety of uses. The project is an 11 story Research and Development facility programmed as operable 24 hours per day. Immediate neighbors include the Greyhound Bus Terminal, The West Precinct Seattle police Department Headquarters, Qwest Communications and, dirctly across the Street, surface parking. These are all active 24 hour operations and contribute to the neighborhood\'s high ambient light level. Considering these factors we have selected lighting for the building which maintains safety for pedestrians while being uniform and understated. along the alley deep shielded Ruud E8-F fixtures are installed at 8\' above the pavement at egress and service doors. On the two street facades at sidewalks, we have utilized Bega 7475MH surface washers mounted at 10\' - 12\' above the walking surface and aimed at the underside of the translucent overhead protection canopies. This provides an even wash of indirect light to the pedestrian walking surface while eliminating the escape of direct light. The fourth side of the building is against the adjacent structure and has no lighting. Three parking levels above street level have cut-off fixtures installed 20\' or more from the exterior walls, further shielded by aluminum screening at the exterior openings to the garage. Lobby lighting is limited to recessed cans, recessesed track and diffuse light from an internally lit large glass sculpture.Our project replaces a surface parking lot that included two unshielded pole area-lights and two 2-sided illuminated billboards. Light level measurements were not taken when these elements were operational so comparative data is not available.I feel that we have responded to both the neighborhood and the credit although the light trespass onto the alley and sidewalks ranges from 2 to 10 footcandles. However, the light trespass onto "adjacent properties" is less than 0.6 footcandles (or 6 lux).I would appreciate your view on this particular situation.
There are multiple components of this CIR that are addressed in the five points below.1. Pedestrian Indirect Lighting: Pages 71 & 72 of the LEED-NC v2.1 Reference Guide discusses design approach strategies to comply with the intent of Sustainable Sites Credit 8. The Guide states "In areas of high ambient brightness, some low level (subtle) lighting of features, facades or landscape areas may be appropriate in pedestrian environments or for identification and way finding" Uplighting a translucent canopy that is continuous around two facades of the building is not consistent with the intent of this credit.To be more consistent with the credit intent, the following steps may help achieve SSc8: (a) Limit uplighting the translucent canopy to key focal points such as main entrances or use opaque material for the continuous canopies. Also, for uplighted areas, provide information about the translucent canopy, showing that the transmittance of the canopy has been minimized. (b) Show that the light distribution is limited to the canopy and does not spill beyond. To help clarify the design, provide a section showing the relationship of the luminaire to the canopy, showing that the photometric distribution from the luminaire is entirely captured by the canopy. (c) Specify a lamp package that has 3500 initial lumens or less. The standard lamp for the Bega 7475MH is a 70 watt metal halide with 6400 initial lumens, which will not meet the credit requirement. (d) Specify a luminaire that has a fixed, non-adjustable mounting. The Bega 7475MH is an adjustable luminaire that would allow changing of the intended aiming after the installation is complete, and refer to item (b).2. Alley Lighting: It is not clear that the Ruud E8-F luminaire meets IESNA Full Cut-off classification, therefore the lamp package must be 3500 initial lumens or less to comply with this credit, or supply documentation showing that the luminaire meets the full cutoff requirements.3. Light Trespass to Alley and Sidewalk: 2 - 10 footcandles far exceeds the limitation of 0.6 as stated in Table 1 on page 70 of the LEED-NC v2.1 Reference Guide. Refer to SSc8 LEED Interpretation Inquiry #5409 (request date 8/16/2003, ruling date 9/2/2003). Include detailed calculations and drawings similar to those on page 75 of the Reference Guide, showing (a) that the light trespass limitation of 0.6 is met at the curb line of the sidewalk of the 2 street sides and (b) that no direct beam illumination will enter any windows of any adjacent properties and that the light trespass is limited to 0.6fc at the window locations in the alley.4. Parking Garage Lighting: For all levels of the parking garage, show that the peak candela of the luminaires falls within the parking garage. If the top level of the parking garage is open to the sky, provide luminaire cutsheets showing that they meet IESNA full cut-off classification, and meet all other exterior requirements.5. Lobby Lighting: From the description provided, the lighting in the lobby satisfies the requirements of SSc8. Provide a diagram and photometric distributions of luminaires showing that the peak candela falls within the building. Note: all other interior lighting must also meet the requirement that the peak candela falls within the building.