Accessible Staircase Design and Handrails

Stairs are the oldest vertical circulation element in architecture — and one of the most dangerous. Falls on stairs account for over one million emergency department visits annually in the United States. For people with low vision, balance impairments, prosthetics, or cognitive disabilities, a poorly designed staircase is not just inconvenient; it is hazardous.

Universal design makes stairs as safe and usable as possible for ambulatory people while complementing them with ramps or elevators for those who cannot use stairs at all.

Staircase requirements are governed by the International Building Code (IBC), ADA Standards for Accessible Design, and local building codes. Handrail standards are specified in both ADA and ICC A117.1.

Tread and Riser Dimensions

Uniformity

The most critical safety requirement for stairs is uniformity. Every riser in a flight must be the same height, and every tread must be the same depth. Even a 3/8-inch variation between risers significantly increases the risk of tripping because the foot expects a consistent rhythm.

Standard Dimensions

Riser height: Maximum 7 inches (IBC). Risers between 6 and 7 inches are the most comfortable and safe.
Tread depth: Minimum 11 inches (IBC). Deeper treads (12 to 13 inches) provide more foot placement surface and greater stability.
Riser-tread relationship: The sum of the riser height and tread depth should fall between 17 and 18 inches for comfortable stride (the “rule of 17”).

Open Risers

Open risers (gaps between treads) are not permitted on accessible routes. They create catching hazards for people using braces, prosthetics, or canes, and they are visually disorienting for people with depth perception difficulties.

Nosing

Tread nosings (the front edge of the tread that projects beyond the riser below) must:

Project no more than 1.5 inches beyond the riser
Have a curved or beveled underside (no abrupt square edges that catch toes)
Be visually contrasting with the rest of the tread (a 1 to 2-inch strip in a contrasting color, such as a dark strip on a light tread)

Contrasting nosings are one of the simplest and most effective safety improvements for any staircase. They help people with low vision identify the edge of each step.

Handrails

ADA and IBC Requirements

Handrails must be provided on both sides of all stairs. Key specifications:

Height: 34 to 38 inches above the stair nosing (measured vertically from the nosing to the top of the gripping surface)
Graspable profile: Circular cross section of 1.25 to 2 inches in diameter, or a non-circular profile with a perimeter of 4 to 6.25 inches and a maximum cross-section dimension of 2.25 inches
Continuous: Handrails must be continuous along the full length of the stair flight. They may not be interrupted at landings if the stair continues in the same direction.
Extensions: Handrails must extend at least 12 inches horizontally beyond the top riser and at least one tread depth beyond the bottom riser, returning to the wall or post. These extensions allow a person to stabilize before stepping onto or off the stairs.

Mounting

Handrails must be mounted so that the space between the handrail and the wall is at least 1.5 inches (so the hand can wrap around the rail)
Handrails must support at least 200 pounds of force at any point along the rail
Fasteners must be concealed or designed so they do not catch clothing or skin

Second Handrail Height

For stairs used by children (schools, community centers), a second handrail at 24 to 28 inches is recommended. This also benefits seated users who are ascending a staircase with assistance.

Stair Width

Minimum width: 44 inches between handrails for stairs serving an occupant load of 50 or more (IBC). 36 inches for lower occupant loads.
Universal design recommendation: 48 to 56 inches for two-way traffic, allowing one person to pass another on the stairs safely.

Landings

Landings are required at the top and bottom of every flight and wherever the stair changes direction
Minimum landing depth: the width of the stair or 48 inches, whichever is less
Landing slope: essentially level (maximum 1:48)
Landings provide rest points for people with limited stamina and help with orientation for people with cognitive impairments

Lighting

Stairways must be well-lit to make treads, nosings, and handrails visible. Recommendations:

100 to 200 lux at the tread surface (IES recommendation)
No shadows cast by handrails or architectural features across the treads
Consistent lighting from top to bottom (avoid bright landings with dim flights)
Light switches at both the top and bottom of the stairs
Photoluminescent markings on nosings, handrails, and landing edges that glow in the dark during power outages (required in high-rise buildings by many codes)

See Lighting Design for Universal Access for detailed guidance.

Stair Lifts

For existing buildings where an elevator or ramp is not feasible, a stair lift (a motorized chair or platform that travels along a rail mounted to the stair) provides vertical access. Stair lifts must:

Not reduce the stair width below the minimum required for egress
Fold or retract when not in use so they do not obstruct the stairway
Have accessible controls operable by the user
Support the rated weight capacity (typically 300 to 400 pounds)

Stair lifts are a compromise, not a universal design ideal. They serve one user at a time and can be slow. Where possible, an elevator or ramp is the better solution.

Materials

Treads: Non-slip surfaces are essential. Textured wood, rubber stair treads, or carpet with low pile provide traction. Polished stone and tile are slippery without applied anti-slip strips.
Handrails: Wood (warm to touch, comfortable grip), stainless steel (durable, easy to clean), or painted metal (can be any color for contrast). Avoid cold metal in outdoor exposed locations unless insulated or coated.

Key Takeaways

Uniform riser heights and tread depths are the most critical stair safety feature — even small variations cause trips and falls.
Contrasting nosings (a 1 to 2-inch strip) help people with low vision identify the edge of each step.
Handrails on both sides, 34 to 38 inches high, with 12-inch extensions at top and bottom, are required by ADA and IBC.
Open risers and abrupt square nosings are prohibited on accessible routes.
Stairway lighting at 100 to 200 lux with no shadows on treads, plus photoluminescent markings, ensures safety in normal and emergency conditions.

For vertical circulation alternatives, see Ramps, Elevators, and Vertical Circulation Design. For the complete framework, visit the Universal Design in Buildings and Architecture Guide.

Sources

2010 ADA Standards for Accessible Design — U.S. Department of Justice
ICC A117.1-2017: Accessible and Usable Buildings and Facilities — International Code Council
Guide to the ADA Standards — U.S. Access Board