Egress

IBC 1011.7, 510.2  

A building constructed using the special provisions of IBC s. 510.2 requires the building below the 3-hour horizontal assembly to be of Type IA construction and allows the building above the 3-hour horizontal assembly to be of any type of construction permitted by the code for the building use, size, and height.  When a fire resistance rated stair enclosure extends through the 3-hour rated horizontal assembly, can the materials used for the stair construction within the rated enclosure be combustible if the building above the horizontal assembly is permitted to be of combustible construction?

Yes. The building below the horizontal assembly is required to be of Type IA fire resistive class of construction which requires with few exceptions the use of noncombustible materials, while the building above the horizontal assembly can be of any class of construction which is appropriate for the building use, size and height. When a fire resistance rated stair enclosure extends through and creates a discontinuity in the horizontal assembly, the fire resistance rated walls of the stair enclosure create the building separation between classes of construction. Therefore, in accordance with IBC s. 1011.7, the stairs within the fire resistance rated stair enclosure can be constructed of combustible materials if the building class of construction above the 3-hour horizontal assembly allows combustible materials to be used in its construction (types III, IV, and V class of construction).

IBC 202 – 6/30/2008

Which passageways* are corridors that consequently must meet the requirements for corridors? 

IBC 202 defines a corridor as an enclosed exit access component that defines and provides a path of egress to an exit and shall meet IBC 1020. Exit access is a portion of the means of egress consists of all floor areas that lead from usable spaces within the building to the exit or exits serving that floor area per IBC 1016, aisles per IBC 1018, or a “convenience path” is not a corridor, regardless of the manner of construction. A corridor, by definition, has full-height walls on both sides, and occupants in a corridor need special protection because the walls (1) cause a sensory isolation from the adjacent spaces of the building and (2) limit the egress paths within the corridor. Even those full-height walls with glazed panels create the defined and enclosed path that is a corridor. There may be short sections of full-height walls in otherwise open egress paths, such as vestibules, that do not create corridors. The triggering criteria, either occupancy classification or number of occupants, when the corridor needs to be protected is in IBC Table 1020.1. 

*Note: For the purpose of answering this question, passageway will be used as a common term instead in terms of the building code. IBC 202 defines an exit passageway as an exit component that is separated from other interior spaces of a building or structure by fire resistance-rated construction and opening protectives and provides for a protected path of egress travel in a horizontal direction to an exit or to the exit discharge and shall meet IBC 1024. It is typically an extension of a stair enclosure or horizontal exit to get occupants to the exit discharge.

IBC 1008.1, 1008.3, and 2702.2.11 – 5/1/2018

Is the use of occupancy sensors permitted as a way of complying with IBC section 1008.1 and assuring the means of egress is illuminated when the space served is occupied?

Yes, the use of automatic controls, like occupancy sensors, is an acceptable way of conserving energy while also assuring the lights will be on during normal use of the spaces. When employing such automatic controls, their use must be incorporated into the design such that they will be overridden by the emergency power system upon loss of normal power. In essence, the switch controllers must be equipped for fail-safe operation.

IBC 1008.2.1 – 6/30/2008

To determine whether an accessible floor is four or more stories above or below a level of exit discharge, do I start counting with the story that is at a level of exit discharge?

To count the stories above, start by finding the highest level of exit discharge. Next find the floor of the story that is above that and you have identified the first story above. From that point you just add. For the stories below, first find the lowest level of exit discharge. Next find the floor of the story that is below that level and you have identified the first story below. From that point you just add stories.

Note: On a flat site, “buildings with four or more stories above the level of exit discharge” would typically be a five-story building.

IBC 1016.2– 9/1/2011 

Are there circumstances other than as specifically listed in the second provision of IBC section 1016.2, where egress is permitted through a room that contains either a storage area or a restaurant-kitchen area?

Yes. The room must (1) be accessory to the area served; (2) include a discernible path of egress travel to an exit; and (3) in the case of a restaurant-kitchen area, include that path outside of the kitchen's work area. For example, a clearly defined path through a large storage room serving a print shop can be part of a path of egress travel, but a small storage room which has a high potential to become crowded and obstructive, or which has locking hardware to prevent egress, should not be included in the path.