I. SITE LIGHTING AREAS AND DESIGN INTEGRATION

Any given building site usually has differing uses and conditions-each has differing lighting requirements as well. Therefore, meeting the diverse needs of site illumination requires a variety of different solutions that can be coordinated and integrated to complement the building design. Such an integrated site lighting design begins with first identifying the specific lighting requirements for each portion of the site, then selecting luminaires that combine appropriate aesthetic design with relevant lighting performance features.

Conceptually, project sites can be classified into four basic lighting areas; roadways, open areas, pedestrian areas, and the site perimeter, each representing a unique set of lighting circumstances, as described below and shown in Figure 1.

Figure 1: Typical Site Lighting Areas 1. Roadways 2. Open Areas 3. Pedestrian Areas 4. Site Perimeter

1. Roadways
Lighting for roadways, including private drive lanes, usually requires uniform light distribution and glare control with wide pole spacings to minimize the total number of luminaires needed. Luminaire selection criteria include overall performance, consideration of maintenance, lamp choices influenced by utility or owner interests, and the ability to remain in service for long periods with minimal attention. Reflectors and optical designs within the luminaires include an array of possible light distribution patterns in order to illuminate varied roadway widths and traffic patterns with narrow perpendicular and wide lateral beam spreads.

2. Open Areas
Lighting of open areas requires careful consideration of illumination requirements, uniformity, and brightness control. These areas are usually subject to scrutiny relevant to the safety and security of site occupants and the interaction between vehicle and pedestrian traffic. Parking areas and connecting walkways, in particular, are a potential source of litigation and liability for the project owner, requiring accurate prediction of illumination levels and dependable performance. In order to optimize visibility for all users, it is important to control illumination levels, uniformity of light distribution, and glare. At the same time, an economical layout will be based on maximizing the spacing of luminaires.

3. Pedestrian Areas
The transition between the surrounding site and the building itself defines the pedestrian area, including plazas, courtyards, and pathways. These spaces require the widest range of lighting solutions since they combine the concerns of open areas and the integration of luminaire appearance with the building's architectural design. Luminaires in this area are usually highly visible, requiring attention to finish quality and detail. Illumination of irregularly shaped spaces, and a need to control stray light, requires optical diversity, particularly since fixture placement may be influenced by aesthetic concerns. Ideally, if the appearance and design components of the luminaires specified in these areas are shared with other site luminaires, the integration of the lighting system for the entire site is enhanced.

4. Site Perimeter
Lighting the site perimeter includes requirements to control or eliminate illumination from "trespassing" onto adjacent properties. Light trespass ordinances, and courtesy to neighboring property occupants, require tight control of light emitted behind the luminaire. Efficient design satisfies some of this demand, while optics inside the luminaire that cut off light distribution in certain areas provide an additional level of control. House-side shields may also be required to provide even tighter control by trimming the distribution pattern. These concerns must be satisfied, of course, without affecting overall system performance.