Chapter 7 of the NFPA 101 Life Safety Code and IBC 1008.3.5 both require a specific amount of foot-candle illumination at the walking surface from the emergency lighting system. A lighting designer considers a great many things when a specific emergency luminaire type is requested including the illumination output levels, mounting height above the walking surface, and luminaire spacing to ensure illumination uniformity.

The design engineer may have gone to great lengths to ensure proper illumination levels when putting the plans together. Detouring from the plans by installing the luminaires higher above floor than specified, or using a different luminaire with lower lumens, or using less luminaires to save money, or even spacing the luminaires too far apart are all things that will have a negative effect on the final performance of the emergency lighting system.

It’s always a good idea to run any field changes by the electrical designer for approval.

One thing the electrical inspector will do at final inspection is carry the plans to each room and verify that the same number and type of emergency luminaires have been installed as shown on the plans.