Spark Notes: Designing Medium-Sized Assembly Spaces in California

But what about assembly spaces that aren’t quite as large? Are there any similar requirements to keep in mind?

Yes, there are. California amendment CBC 1030.3.1 mandates more direct egress routes for assembly spaces with an occupant load of 100 to 300, which exceeds the requirements of the model code.

Complying with CBC 1030.3.1 Requirements

This provision guides the location and arrangement of these spaces within the building. Complying with CBC 1030.3.1 can be challenging, especially for assembly spaces above the exit discharge level. Notably, the exits selected to meet the requirement must open to the exterior where there is plenty of space for occupants to move away from the building.

In California, an assembly space with 100-300 occupants requires:

• At least two remotely located exits separated from each other (described in CBC 1007.1.1).
• Common paths of travel from every point within the space limited to 75 ft (CBC 1006.2.1).
• Doors swinging in the direction of egress travel with panic hardware (CBC 1010.1.2.1 and CBC 1010.2.9).
• Exit signs (CBC 1013.1).

In addition to these requirements, at least one of the exits must meet the CBC’s amended requirement, including discharging to an open space and complying with one of the following:

• A door from the assembly space must lead directly outside (exit discharge) or into an exit, like a stairway enclosure (CBC 1030.3.1, provision 1).
• An egress route can pass through a non-rated lobby to reach an exit discharge or stairway, as long as the lobby is not used to access the second required exit for the assembly space (CBC 1030.3.1, provision 2).
• A door from the assembly space must open into a one-hour rated corridor leading to an exit discharge or an exit such as an exit stairway enclosure (CBC 1013.1, provision 3).
• An egress route from the assembly space can pass through a one-hour rated lobby leading to an exit discharge or exit stairway (CBC 1013.1, provision 4).

Any of the above approaches will do, and each provides a more direct egress route than the model code requires. The presence of rated construction (or a direct exit) reduces the chance that a fire somewhere outside the assembly space can obstruct multiple egress opportunities from the space. With those requirements in mind, one other CBC provision must be met:

• At least one exit from the assembly space must discharge onto a street or an unoccupied space of not less than 20 ft wide that adjoins a street or public way. This requirement for a wide exterior space allows occupants to easily move away from the building once they have reached the exterior.

Figures 1 and 2 show options for compliant egress from these assembly spaces.

Additional Design Considerations

Project teams should also take several other factors into account during the design process:

• The proximity of an assembly space to an exit is critical when incorporating it into a new design. When arranging the assembly spaces for the building, these spaces should be located near egress opportunities.
• If an assembly space is situated along the building’s exterior wall, a direct exit to the outside may be the simplest solution. However, this approach requires that the exterior provides an appropriate exit discharge condition.
• If an assembly space is located deeper within the interior of the building, then a lobby or fire-rated corridor can be used to meet the requirements.
• If an assembly space is on an upper level (such as a rooftop terrace or an event space), an exit stairway enclosure directly adjacent to the space is valuable. The proximity of this required exit will help avoid extensive wall ratings that would not otherwise be required.

A qualified fire life safety consultant can assist project teams and stakeholders in understanding code updates and their potential project impacts.