Guide to Building Codes for Stairs & Railings

Here we illustrate and summarize typical building code requirements for stairs, railings, landings, and guardrails. We also include references to key building codes that provide more detailed specifications for stair, landing, and railing safety.

Because more people are injured by trips and falls than other hazards, experts have looked closely at the specifications for stairs, steps, and rails to reduce the falling hazards.

This article has been adapted from specific stair and railing specifications that are similar among codes and countries (but not identical). -- IBC, IRC, BOCA, Kingston NY Stair Code, New York State Residential Building Code for Stairs (included here), Florida, Pennsylvania, New Jersey, & other sources.

In-depth stair design articles listed at the "More Reading" links at the bottom of this article provide detailed descriptions of each stair feature, building codes, photographs and sketches of defects and requirements. Text comparing key provisions of several building code sections on stairs and rails is given at the end of this document. We provide sketches and photographs of stair, railing, landing, and construction details and hazards

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sketch courtesy Carson Dunlop Associates.

 

Balusters for Guards & Railings

Stairway handrail & stair balusters & guard details are in this sketch.

A summary is below.

Balusters (vertical posts comprising the barrier in guards and railings)

  • Baluster opening between vertical members (maximum sphere passage <= 4 3/8")

  • Baluster opening in triangular area below guard bottom rail and stair tread (maximum sphere passage <= 6")

Hand-railing heights are given:

  • U.S. handrails for stairs with one side against a wall: 30-38"

  • U.S. handrails at open stairs: 34-38" above the stairs

  • Canadian stair handrails: 32-36" above the stairs

  • Wall clearance: Handrails along a wall must have at least 1.5" of clearance between the inside surface of the rail and the wall surface.

  • Railings should not project into the required width of the stairway by more than 4.5" at or below the handrail height above the stairs.

Sketch courtesy Carson Dunlop Associates.

Stairway Height, Width, Headroom Code Specifications & Requirements

Stairway headroom (=> 6'8" over tread or landing) Stairways shall have a minimum headroom clearance of 80 inches (2032 mm) measured vertically from a line connecting the edge of the nosings.

Such headroom shall be continuous above the stairway to the point where the line intersects the landing below, one tread depth beyond the bottom riser. 

The minimum clearance shall be maintained the full width of the stairway and landing. - NYS

Headroom is allowed to be reduced to 78" over spiral stairs in some codes such as New York State.

Sketch showing stairwell width and landing details is provided courtesy Carson Dunlop Associates.

Stairwell width and stair landing platform requirements are summarized by this sketch.

The minimum recommended stair width is between 34" and 36" ACROSS.

The minimum recommended stair landing length is 36" (or a length and width sufficiently greater than the swing of the door if a wider door is present.

Notice that a stair top landing is not required if the door at the top of the stair opens away from the stairwell.

In these sketches required handrails have been omitted for clarity.

1009.1 Stairway width. The width of stairways shall be determined as specified in Section 1005.1, but such width shall not be less than 44 inches (1118 mm). See Section 1007.3 for accessible means of egress stairways.

Maximum Permitted Height for Stairways - between floors or landings

1009.6 Vertical rise. A flight of stairs shall not have a vertical rise greater than 12 feet (3658 mm) between floor levels or landings.

This means that if the floor to floor height traversed by a stairway is more than 12 feet of vertical distance, one or more landings is required.