ID#5768 made on
SSc1 - Site selection
LEED ID+C: Commercial Interiors
Our project, a 485,000 sf commercial office TI, is located on part of a larger campus owned by one landlord. The entire East boundary of the project site is adjacent to a new commercial development ow...
Our project, a 485,000 sf commercial office TI, is located on part of a larger campus owned by one landlord. The entire East boundary of the project site is adjacent to a new commercial development owned by the same landlord. The new site will have (3) mid-rise commercial office buildings totalling 1 million sf and (2) parking garages. Adjacent to the northern boundary of the site is a residential/commercial collector street which connects to a major bike/running path. The street is well lit to provide a safe environment for joggers and bikers at all hours. The site is classified as LZ3 per IESNA RP-33. Although this project is registered under LEED CI 2.0, the team used the language of this credit in the LEED NC 2.2 rating system to determine whether the project met the intent of the credit. The project team ran a site illuminance study to determine if illuminance values of "no greater than 0.20 horizontal and vertical footcandles at the site boundary and no greater than 0.01 horizontal footcandles 15 feet beyond the site" occurred. The team found that the existing site lighting produced light levels greater than the aforementioned maximums in a very few locations. At the East site boundary, illuminance levels of greater than 0.01 footcandles occur in two locations - the maximum value at the East boundary was found to be 0.28 footcandles at 15 feet beyond the site boundary. At the northern site boundary in the northeast corner of the site, a maximum illuminance of 0.04 footcandles occurs at 15 feet beyond the site boundary. In order to correct this issue, the team would have to shield the existing pole light fixtures. However, shielding the (3) pole fixtures which cause this light trespass would lower light levels in the East perimeter parking spaces to lower than those recommended by IESNA #RP-20-98, which states that a minimum lighting level of 0.5 is recommended for enhanced security. As these spaces are furthest from campus security cameras, light is imperative in these areas for tenant safety. However, the project team believes that since the adjacencies to the North and East are commercial properties and heavily trafficked areas, they will not be disturbed by this light trespass. The properties adjacent to the East and northeast corners of the site will not be receiving unwanted light; the street to the north is already well lit at all hours beyond the levels of the light trespass; the property to the East is owned by the same landlord and contains similar and larger commercial structures. In addition, the property to the East sits at a higher elevation than our project (approximately 12 feet along the East property boundary), further precluding any disturbance from the light trespass. Moreover, the existing lighting levels at these adjacencies are much greater than the light trespass occurring from our project's site. Existing light trespass that occurs along the West and South boundaries (which abut a canyon and a residential neighborhood) will be corrected by appropriate shielding of the existing fixtures. The team believes that the intent of this credit is met. Our current lighting design meets all other requirements of this credit. All light sensitive adjacencies will be protected while appropriate light levels for safety and comfort will be provided at the parking area for the project's tenants.
With the information provided this project does not meet the intent of SSc8 in limiting light trespass off of the site. Numerous CIRs have addressed this issue when a project exceeds the lighting trespass limits set forth by IESNA RP-33-99 at a few locations for the zone where the building is located. Please refer to LEED-NC v2.1 SSc8 CIR ruling 12/2/2006 and 10/2/2006 for more information. The description provided by the applicant indicates that the project team has made an effort to meet the requirements of this credit; however, the argument that the adjacent property is owned by the same owner is not acceptable. Similarly, only code mandated lighting levels can be accepted as a reason for having slightly higher lighting levels at certain locations for security reasons, and the proponent must document the specific code requirement. Moreover, for site boundaries that abut public rights of way (Northern boundary in your case-next to the residential /commercial collector street), light trespass requirements may be met relative to the curb line instead of the site boundary. In all areas the light trespass 15ft beyond the property/curb line must meet the 0.01fc requirement. Furthermore, when submitting for LEED review, the project team must thoroughly review the requirements of IESNA RP-33-99 and the local code or any other relevant guidelines and provide adequate justification to demonstrate that the project meets the intent of this credit. The project team should also consider consulting the LEED-NC application Guide for Multiple Buildings and On-Campus Building Projects, as it has been indicated that the project abuts another building with the same owner.
Update April 15, 2011: Please note that all 2009 projects in multiple building situations must follow the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987. 2009 project teams should check this document for up to date guidance on all multiple building issues. Applicable internationally.
Related Addenda (Corrections & Interpretations)