Interpretation #: CEB-2020-30-2020 IRC-R311.3

Building or Fire Safety Law Interpreted

675 IAC 14-4.4, 2020 Indiana Residential Code, Section R311.3 Floors and landings at exterior doors.

There shall be a landing or floor on each side of each exterior door. The width of each landing shall be not less than the door served. Landings shall have a dimension of not less than 36 inches (914 mm) measured in the direction of travel. The slope at exterior landings shall not exceed 1/4 unit vertical in 12 units horizontal (2 percent).

R311.3.1 Floor elevations at the required egress doors.

Landings or finished floors at the required egress door shall be not more than 1 1/2 inches (38 mm) lower than the top of the threshold.

Where exterior landings or floors serving the required egress door are not at grade, they shall be provided with access to grade by means of a ramp in accordance with Section R311.8 or a stairway in accordance with Section R311.7.

R311.3.2 Floor elevations at other exterior doors.

Doors other than the required egress door shall be provided with landings or floors not more than one stair riser below the top of the threshold.

R311.3.3 Storm and screen doors.

Storm and screen doors shall be permitted to swing over exterior stairs and landings.

Issue

Whether, under Section R311.3 of the 2020 Indiana Residential Code (IRC), an exterior stair is required to have a top landing when that stair serves an exterior door that is not required for egress, has a threshold elevation 30 inches or less above adjacent grade, and the only outward-swinging door at that opening is a screen or storm door.

Interpretation of the State Building Commissioner

An exterior stair does not require a top landing when the exterior door served by that stair is not required for egress, has a threshold elevation of 30 inches or less above adjacent grade, and the only outward-swinging door at that opening is a screen or storm door.

Rationale

Section R311.3.2, a subsection of R311.3, includes an exception that allows an exterior stair to have no top landing, if it meets three specific criteria: 1) the exterior door served by the exterior stair must not be a required egress opening; 2) the difference in elevation between that exterior door's threshold and adjacent grade at the opening is 30 inches or less; and 3) that exterior door may not swing out over the exterior stair.

Section R311.3.3, also a subsection of R311.3, states that storm and screen doors are specifically permitted to swing out over both exterior stairs and exterior landings.

The two subsections taken in tandem result in a condition in which it is permitted to omit a top landing at an exterior stair if the exterior door served by the stair is not required for egress, the elevation difference at that exterior door is 30 inches or less, and the only door at that opening that swings out over the stair is a screen or storm door.

It is important to understand that Section R311.3.3 is not in conflict with Section R311.3 or any of R311.3's other subsections. While this could have been made more clear had the authors included the out-swinging screen/storm door allowance as a permitted exception within the text of both R311.3.1 and R311.3.2, they chose instead to write it once, as another subsection in its own right. Nevertheless the statement is intended to act in concert with the previous two subsections, this being confirmed in IRC commentary, which says, "Sections R311.3.1 and R311.3.2 both have allowances for landing elevations when the door does not swing out over the landing. A common scenario is to have both a screen door and a wood/metal door at the front and/or rear entrance to the home. The screen door swinging out over the landing would not violate these exceptions." (Emphasis added.)

It must be understood that the organizational hierarchy of Section R311.3 and its subsections is not intended to establish regulatory precedence when applying the requirements contained therein, and it should not be used to resolve what might appear to some to be conflicts in those requirements. Rather, R311.3 states a general requirement, and its subsections explain that requirement in detail, modify it if necessary, and even provide circumstances in which the general requirement does not apply. If the "landing or floor on each side of each exterior door" required by Section R311.3 were always to supersede the exception allowances provided in its three subsections (R311.3.1, R311.3.2, and R311.3.3), there would be no reason for those subsection allowances to exist other than by error. They are not errors.