Maximum Stair Riser

8 inch maximum riser height for residential stair building code

The maximum stair riser can't be larger than 7 inches or smaller than 4 inches. The riser measurement will be from the top of the lower step to the top of the next step above.

 

Reference: 2012 International Building Code - 1009.7 page 254

Reference: 2012 International Residential Code - R311.7.5.1 Page 60

However, there are is an exception for most single-family homes that can have a maximum of 7 3/4" inches.

Now where does the 7 inch maximum riser height come into play. This building code applies to residential buildings with more than 50 occupants. Most building codes clearly state that an 8 inch maximum riser (except for the 2010 California building code, requiring a 7 3/4" maximum riser) is acceptable for buildings with less than 49 occupants.

If you're planning on building any stairs that aren't going to be used for a private residence (public stairs) with less than 49 occupants, plan on using risers between 4 and 7 inches in height.

Attention: Don't forget to check with your local building department to verify any building codes on this website. This information could be incorrect or outdated. Building codes are updated regularly and to some building departments have different interpretations for certain building codes.

how to measure riser hieght for building code

Here's another picture, just in case you're having problems trying to figure out how to measure the maximum individual stairway rise. In the picture above there is no tread nosing and you will simply measure vertically or up-and-down the distance in between each individual step.

If you have any problems, feel free to e-mail us with your questions.