PPP Notes - Site Lighting

SITE ELECTRICAL UTILITIES

 (These notes are compiled from AGS)

SITE LIGHTING

 

• Creating good design for site lighting is not just about picking the latest technology or the best fixture.  It is about using lighting to convey the overall story of a project. 
• The story may be one of safety in a casino parking lot or it may be one of excitement in an outdoor mall where visitors can gather with their families for an evening to have dinner and see a movie.
• Site lighting design requirements vary from project to project, and so need to be defined with the individual project team prior to preparing a design.
• Site lighting requirements typically include lighting pedestrian pathways, landscaping, landscape features, water features, and architectural features such as statuary and adjacent public roadways, parking areas, and nearby facades.
• Site lighting design, at its core, is about lighting the environment in a manner that responds to the desired function of the guests within the space.
• There may be multiple functions such as wayfinding, creating gathering spaces, interacting with the organic and built environments, and meeting security requirements, which all must be taken into account.
• The overall design intent of the space must allow for these functions to coexist seamlessly, or the guest experience will be negative.
• As a part of the design preparation, designers will want to familiarize themselves with the landscape design and current foliage specifications on the project.
• Lighting fixtures can be used to highlight trees, accent shrubbery, and be mounted in trees to light the path below.
• It is important to know which trees are deciduous and which trees retain their canopies when making these determinations.
• It is also highly recommended that lighting designers work closely with the landscape architect to understand which trees will allow the attachment of lighting hardware and mounting straps.
• Once the site lighting tasks and requirements have been determined, the designer can begin selecting fixtures, determining lamp types, and preparing the layout.

 

SITE LIGHTING REGULATIONS AND CODES

 

• Other factors to consider when designing site lighting are local and national energy codes, any locality-specific dark-sky ordinances, and the current lighting levels in the surrounding and adjacent areas.
• The International Dark-Sky Association (IDA) is a nonprofit group whose mission is “to preserve and protect the nighttime environment and our heritage of dark skies through quality outdoor lighting.”
• This association (www.darksky.org) has been an active voice in the creation of many of the local dark-sky ordinances.
• Several calculation programs are available to help verify the illuminance levels are being met in the site lighting design. 
• AGI32 (www.agi32.com) is commonly used for site lighting studies as is LumenMicro by Lighting Technologies (www.lighting-technologies.com).
• The most difficult part of creating a good lighting design is to meet all of the functional and code requirements of a site while mixing in the desired aesthetics of the project.
• Providing the right nighttime identity for a site is key to making any project a success.

 

SITE LIGHTING DOCUMENTATION

 

• Required documentation for the lighting design submittal will vary from project to project, but the basic elements will remain the same.
• A minimum of suggested documentation would include:
• A layout depicting the design intent
• Fixture cut sheets and specifications showing fixtures desired on the project.
• Mounting details showing any special integration requirements.

 

AREA LIGHTING

 

• Path lighting fixtures generally include pole/post lighting, bollards, and step lights.
• Pole lighting can be decorative to match the architecture, make a statement, or be purely functional.
• Pole, post, and bollard heights and spacing are determined by calculating the desired and/or required illuminance values, along with creating a layout that meets the aesthetic qualities as determined by the project design team.
• As a general rule, the minimum mounting height should be no less than one-half the maximum project distance from a single fixture head.
• When using poles, posts or bollards, designers should be prepared to coordinate anchor bolt details and the need for any additional foundations required to meet local wind-loading requirements.
• Project engineers should be consulted, as well as the fixture manufacturer, to confirm the product can meet the wind-loading requirements.
• Mounting details should be customized for any site-specific requirements, and the specified manufacturer should be treated as a valuable resource for the information needed to complete this effort.
• It is also highly recommended that the Illuminating Engineering Society of North America (IESNA) by a key resource for all projects located within North America. 
• The IESNA has compiled a series of recommended lighting requirements and illuminance values for many of the tasks involved in creating the site lighting.
• There is a variety of lighting illuminance levels, depending on the adjacent architecture.
• For example, a bank parking lot may require higher levels of illuminance, due to security issues, than those of a library parking lot on the same street.
• The KIM theory of relativity says, “Poles belong in parking lots.  And, once you leave the parking lot, the outdoor lighting should become less and less conspicuous until it becomes an integral part of the architecture.”
• In addition, the luminaire style and geometry should remain consistent.  
• SITE/ROADWAY ZONE LIGHTING: Parking lots and roadways require luminaires on 20’-40’ poles to efficiently light these large areas.  Therefore, this lighting becomes dominant, and sets the design and style for all other lighting as you progress towards the building.
• PEDESTRIAN ZONE LIGHTING: As you leave the parking lot and transition to pedestrian areas, poles should decrease in height, to 10’-16’.  In addition, luminaires should decrease in scale, and can have more decorative features to be appreciated at the pedestrian level.
• LANDSCAPE/PATH ZONE LIGHTING: Near the building, luminaires should begin to disappear, blending into the landscape and hardscape elements.
• BUILDING/PERIMETER LIGHTING: No pole-mounted luminaires should ever be used near the building, as they will dominate the architecture.  The only exception would be the use of decorative luminaires to delineate entrances to the structure.  Building mounted, architecturally compatible fixtures should be almost invisible.