1. Landscape, Building Facade, and Site Illumination Lighting Michael W. Higdon Lighting By Design, Inc. Copyright 1996-98 © Dale Carnegie & Associates, Inc.

13. Safety & Security Lighting Safety can be defined as freedom from danger, whereas security is freedom from worry. Security is often considered the psychological version of safety. Features of the environment that compromise safety can be identified and illuminated, but because security involves psychology as well as vision, it is a more difficult design criterion for exterior lighting. In general, comfortable, well-defined exterior environments with clear zones of recognition are perceived as secure. This design approach provides a feeling that there is enough response time to avoid or escape potential threats. People often associate higher illuminance or greater luminance with safer surrounds, but poorly directed light can reduce visibility and thereby reduce both safety and security.

14. Light Pollution Dust, water vapor, and other particles reflect and scatter light that is emitted into the atmosphere. The result is the sky glow found over all urban areas, sometimes called atmospheric or astronomical light pollution. Although this sky glow is not injurious, it does deprive urban residents of the opportunity to stargaze and can hamper astronomers' attempts to view the night sky through telescopes.

16. Light Trespass The topic of light trespass is somewhat subjective, because it often relates to unmeasurable and undefinable factors. A typical example is the "light shining in my window" complaint. A simple solution to this problem is to shield the offending luminaire so that its luminance is not directed toward the complainant. Light trespass usually falls into one of two categories: unwanted light received in adjacent properties (high illuminance levels), and excessive brightness occurring in the normal field of vision (nuisance glare). Efforts have been made in numerous jurisdictions to write ordinances or laws controlling light trespass.

19. Successful exterior lighting design employs layers of light. Layered lighting provides minimal ambient illumination with accents on hazards, destinations, and architectural features. Sidewalks, trees, and building facades can be used as reference points and backdrops for such important features as crosswalks and intersections on roadways, or stairs and changes in elevation on pathways. Highlights can also be provided on gathering places and on interesting features such as bridges, statues, or plantings. Layered lighting defines the spatial characteristics of the environment and helps minimize dark areas that would otherwise serve as areas of concealment.

20. Landscape and Site Illumination Let There be Light!

21. REFERENCES 1. IESNA. Committee on Sports and Recreational Lighting. 1988. Current recommended practice for sports and recreational area lighting, IES RP-6-1988. New York: Illuminating Engineering Society of North America. 2. IES. Roadway Lighting Committee. 1983. American national standard practice for roadway lighting, ANSI/IES RP-8-1983. New York: Illuminating Engineering Society. 3. IES Roadway Committee. Subcommittee on Off-Roadway Facilities. 1998. Lighting for parking facilities, IES RP-20-1998. New York: Illuminating Engineering Society of North America. 4. IESNA. Roadway Standard practice Subcommittee of the IESNA Roadway Lighting Committee. A discussion of Appendix E--Classification of luminaire light distributions from the American National Standard for Roadway lighting RP-8-1983 Roadway Lighting, TM-3-1995. New York: New York: Illuminating Engineering Society of North America. 5. The IESNA Recommended Practice for Lighting Merchandising Areas, IES RP-2-1985 is under revision. Expected publication date is Spring 2000. 6. Rea, M. S. 1996. Essay by invitation. Light. Des. Appl. 26(10): 15-16.

22. 7. He, Y., M. Rea, A. Bierman, and J. Bullough. 1997. Evaluating light source efficacy under mesopic conditions using reaction times. Journal of the Illuminating Engineering Society of North America 26(1):125-138. 8. IESNA. Outdoor Environment Lighting Committee. 1999. Lighting for exterior environments: An IESNA recommended practice, RP-33-1999. New York: Illuminating Engineering Society of North America. 9. IESNA. Ballast Task Force. 1996. Ballasts and the generation of light, DG-8-96. New York: Illuminating Engineering Society of North America. 10. Moyer, J. L. 1992. The landscape lighting book. New York: John Wiley. 11. National Fire Protection Association. 1999. National electrical code, NFPA 70. Quincy, MA: National Fire Protection Association.