R311.3.2

Section R311.3.2 is titled 'Floor elevations at other exterior doors' and covers the requirements for elevation changes at exterior doors, other than the required egress door. The purpose of this section is to reduce the risk of trip and fall hazards, but to yet allow for designs that are not as stringent as for the required egress door. This section has an exception which allows for no landing, where there is a stairway with no more than two risers on the exterior side of the door. The purpose of this exception is to allow for space saving designs, where there is a lower risk of trip and fall.

The model shows 3 exterior doors, that are not required egress doors, side-by-side for comparison. The first door depicts a design that is allowed by this section, but not allowed for the required egress door, i.e., an outward swinging door over the landing. (The landing is 7-3/4" below the top of the threshold). The middle door depicts a design that is allowed for both the required egress door and any other exterior door. The third door depicts the exception with a two-riser stairway leading to the exterior of the door. Notice that there is an elevation change between the top tread and the threshold. Is this elevation change considered one of the risers of the stairway? The model presumes that it is not, and thus it does not need to conform with the stairway riser height consistency requirements of section R311.7.5.1. In other words, the top tread to the top of the threshold could be any dimension from 0 to 7-3/4", regardless of the stairway riser dimensions.