When it comes to egress lighting requirements, there is conflicting verbiage between the Life Safety Code (NFPA 101), the Uniform Building Code (UBC), and the International Building Code (IBC). This conflict can lead to varying interpretations of egress lighting requirements from jurisdiction to jurisdiction for both interior and exterior areas of commercial buildings.
A good place to start is with a review of the requirements outlined for egress lighting in each of these three important codes.
Life Safety Code
Section 188.8.131.52 of NFPA 101 states, “The floors and other walking surfaces within an exit and within portions of the exit access and exit discharge designated in 184.108.40.206 shall be illuminated to values of at least 1 footcandle measured at the floor.”
Section 220.127.116.11, “Performance of Systems,” dictates the following: “Emergency illumination shall be provided for a period of 1½ hours in the event of failure of normal lighting. Emergency lighting facilities shall be arranged to provide initial illumination that is at least an average of 1 footcandle and a minimum at any point of 0.1 footcandle measured along the path of egress at floor level. Illumination levels may decline to 0.6 footcandles average and a minimum at any point of 0.06 footcandles at the end of the emergency illumination lighting time duration. A maximum to minimum illumination uniformity ratio of 40-to-1 shall not be exceeded.”
Uniform Building Code
Section 1003.2.9.1 of the UBC states, “Any time a building is occupied, the means of egress shall be illuminated at an intensity of not less than 1 footcandle at floor level.”
International Building Code
Section 1006.2, Illumination Level, of the IBC states, “The means of egress illumination level shall not be less than 1 footcandle at the floor level.”
Section 1006.4, Performance of Systems, states: “Emergency lighting facilities shall be arranged to provide initial illumination that is at least an average of 1 footcandle and a minimum of any point of 0.1 footcandles measured along the path of egress at floor level.”