Means of egress lighting is essential for the safe and quick evacuation of buildings. It is for this reason that the building and fire codes have strict requirements on illumination levels within and outside of buildings under both normal and emergency conditions at all times that buildings are occupied with limited exceptions.
Along the entire means of egress, a minimum lighting level of 1 footcandle is required to be maintained. The lighting intensity provided by 1 footcandle is approximately equal to that found outdoors during twilight. To put it in perspective, a sunny day has an intensity of approximately 10,000 footcandles.
It is important to remember that “means of egress” is defined as consisting of three parts: the exit access, the exit, and the exit discharge. This results in lighting being required along the entire path of travel from within occupied spaces to the public way including open plan egress (i.e. open office), exit access aisles, corridors, stairs, exit doors, exterior doors, and along the entire path of travel from the exterior door to the public way. This may require many low level lighting appliances to be provided along exterior walkways until an egressing individual reaches a public way such as a city road.
Under emergency power loss conditions, emergency lighting is required to provide an average illumination intensity of 1 footcandle at walking surfaces for a 90 minute period of time. The areas provided with illumination are not as extensive as are required for normal egress lighting. For instance, areas such as the exterior discharge path are not required to be provided with emergency lighting. Certain rooms, regardless of their occupant load or egress arrangements, which are critical to life safety are required to have emergency lighting including fire command centers, fire pump rooms, large bathrooms, generator rooms, and electrical equipment rooms.
1. Can we provide an average illumination of 1 footcandle along walking surfaces?
1 footcandle is required as a minimum intensity under normal conditions. An average illumination is only permitted under emergency power.
2. Is means of egress lighting required at all times?
Means of egress illumination is required at all times the building is occupied. Lighting is not required to be provided if people are not inside.
3. Is illumination required within assembly spaces?
For assembly spaces such as theaters and auditoriums there are allowances for reduced lighting during performances.
Please do not hesitate to contact us if you have means of egress lighting questions and how they apply to your specific project.