How to Measure the Clear Egress Width of a Stairway

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April 27, 2018

Under the Massachusetts State Building Code, 780 CMR, the width of a stairway is typically measured from outside stringer to outside stringer. Stairways are required to have a minimum width of 44”. Handrails are permitted to project into the required minimum width by a maximum of 4 ½” on each side of the stair.

If a floor has a total occupant load of less than 50 people, the minimum width of a stairway can be reduced to 36”.

In non-sprinklered buildings, stairways serving as an accessible means of egress are required to provide a minimum width of 48” between the handrails. Additionally, exterior stairs serving as a means of egress for an exterior area for assisted rescue are also required to provide a minimum width of 48”’ between handrails.

Have questions on how this affects your design? Contact us with questions regarding minimum stair widths!

Application of any information provided, for any use, is at the reader’s risk and without liability to Code Red Consultants. Code Red Consultants does not warrant the accuracy of any information contained in this blog as applicable codes and standards change over time. The application, enforcement and interpretation of codes and standards may vary between Authorities Having Jurisdiction and for this reason, registered design professionals should be consulted to determine the appropriate application of codes and standards to a specific scope of work.