Egress Width

Egress Stair Bottleneck, Exit Stair Bottleneck

The minimum width required for components of a MEANS OF EGRESS SYSTEM is outlined in BC Section 1005 Egress Width.

Egress components include egress stairs, corridors, exit passageways and exit doors. There are additional requirements outlined in other sections of the building code regarding the width of egress stairs, corridors and exit passageways.(See below for more info on each egress component.) These can be more strict than the requirements of BC Section 1005. But you still need to show calculations demonstrating that all egress components comply with TABLE 1005.1.

Building Code Section 1005 requirements

You must first calculate the occupant load of the space being served by the egress component.

Then the minimum width of the egress component is calculated by using the appropriate factor from Table 1005.1

OCCUPANT LOAD X inches per occupant according to TABLE 1005.1 = WIDTH OF EGRESS COMPONENT
egress width table

TABLE 1005.1 Egress Width

Exit Stair Width

In addition to Table 1005.1, egress stairs are required to comply with BC Section 1009.1.
Refer to this post for more info.

Egress Corridor Width

In addition to Table 1005.1, corridors are required to comply with BC Section 1016.2. Refer to this post for more info.

Exit Passageway Width

In addition to Table 1005.1, exit passageways are required to comply with BC Section 1020.2Refer to this post for more info.

Exit Door Width/ Exit Door Capacity

For the most part BC Section 1005 determines the minimum width required for exit doors. However, there are a few more things to consider. Refer to this post for more info.

Other Components

The most common components of a means of egress system were included in this post. However, there are other components that can be a part of a means of egress system that were not included here. If there is a particular component that you have a question about, please post in the comments and I will add it as soon as possible.

Easily Overlooked Egress Width Mistakes to Avoid

“Multiple means of egress shall be sized such that the loss of any one means of egress shall not reduce the available capacity to less than 50 percent of the required capacity.”
- BC Section 1005.1

This most often affects the required width of the exit door.

“The maximum capacity required from any story of a building shall be maintained to the termination of the means of egress.”
- BC Section 1005.1

This most often affects the required width of exit stairs and the required width exit passageways.

“Once a given level of exit protection is achieved, such level of protection shall not be reduced until arrival at the exit discharge.”
- BC Section 1017.1

This most often affects the required width of exit stairs and the required width exit passageways.


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