Crime Prevention Through Environmental Design (CPTED) Standards

According to the CPTED (Crime Prevention Through Environmental Design) recommendations/guidelines, you want to have at least 1 foot candle power minimum maintained in open parking lots, more for parking structures. This is the standard used in the California Model Security Ordinance.

Minimum maintained means that, on average, there will be 1 ft candle evenly distributed per square inch of the parking surface. When you are talking with a lighting supplier, they may try to sell you on 1 ft candle average maintained. Average maintained means that the ft candle quoted will be between 3 and 5 feet above the ground and will leave you with patches of darkness at the ground level.

As for the type of lighting, I would suggest using either High or Low Pressure Sodium Vapor Lights. Both have long lasting life spans. HPSV's have about a 24,000 hour life and they will maintain approximately 90% of their original lumen rate during this time. LPSV's last between 18,000 and 20,000 hours and also maintain their original lumen rate for most of their life expectancy. LPSV's have a yellow light that allows the human eye to pick up greater details in most weather conditions and they are slightly brighter than the HPSV's, but the light can distort colors at night (i.e., red can appear as brown). HPSV's produce a white light at about 1/2 the energy consumption. Both do require a longer warm up period than other traditional lights, but this can be overcome by using a photocell set properly to turn the lights on as dusk starts.

If you would like any additional information on lighting or CPTED principles, just let me know. I can photocopy some information and send it to if you'd like. There are also some very good Internet resources and books out on CPTED as well. I would suggest you determine what your want in the way of lighting (type, # of ft candles 'minimum maintained', photocells vs timers, transitional lighting, how and where to use reflectors and refractors to direct and disperse your lighting, use or future use of CCTV's, etc), then get with an engineer to design the lighting around your desired specifications. If you leave it to an engineer alone, it may not necessarily provide the desired outcomes you would like. They tend to design systems that use a ft candle system with 'average-maintained' lighting standards or that are more esthetically pleasing vs security conscious.