EZUD Ramps, Elevators, and Vertical Circulation Design
Ramps, Elevators, and Vertical Circulation Design
Vertical circulation — the system of ramps, elevators, lifts, and stairs that moves people between levels — determines whether a building is truly accessible or only accessible on paper. A beautiful ground-floor entrance means little if the second floor is reachable only by stairs.
This guide covers the design standards, code requirements, and best practices for each vertical circulation element in universally designed buildings.
Code requirements vary by jurisdiction and building type. The standards cited here reflect the ADA Standards for Accessible Design and ICC A117.1-2017. Always confirm local requirements with your building official.
Ramps
Ramps are the most common solution for overcoming small elevation changes, typically up to 30 inches. They serve wheelchair users, people with strollers, delivery workers, and anyone who has difficulty with stairs.
Slope Requirements
The ADA mandates a maximum running slope of 1:12 (one inch of rise for every 12 inches of run). This means a 30-inch elevation change requires a ramp at least 30 feet long. For exterior ramps exposed to weather, a gentler slope of 1:16 or 1:20 is recommended to maintain traction in wet or icy conditions.
The cross slope (side-to-side tilt) must not exceed 1:48.
Width
The minimum clear width between handrails is 36 inches. For high-traffic areas such as hospital corridors or school exits, 48 to 60 inches allows two-way wheelchair traffic.
Landings
Level landings are required at the top and bottom of every ramp run and wherever the ramp changes direction. Landings must be at least 60 inches long and at least as wide as the ramp. A ramp run between landings must not rise more than 30 inches.
Handrails
Handrails are required on both sides of any ramp with a rise greater than 6 inches. They must be between 34 and 38 inches high, with a graspable profile (circular cross section of 1.25 to 2 inches in diameter). Handrails must extend 12 inches beyond the top and bottom of the ramp run.
Edge Protection
Curbs, walls, or railings at least 4 inches high along the ramp edges prevent wheelchairs from rolling off the side. This is required on all ramps.
Elevators
Elevators are the primary means of accessible vertical circulation in multi-story buildings. The ADA requires at least one accessible elevator in buildings where an accessible route connects levels.
Cab Size
The minimum interior cab size for a passenger elevator under ADA is 51 inches deep by 68 inches wide (with a center-opening door) or 51 inches deep by 54 inches wide (with a side-opening door). These dimensions allow a wheelchair user to enter, turn, and reach the controls.
For stretcher-accessible elevators in healthcare facilities, larger dimensions apply.
Controls
Elevator controls must be mounted between 15 and 48 inches above the floor (the ADA reach range). Buttons must have raised characters and Braille. A tactile star identifies the main entry floor. Audible signals indicate floor arrival and direction of travel.
Door Timing
Elevator doors must remain open long enough for a person using a wheelchair or walker to enter. The minimum door-open time is calculated based on the distance from the hall call button to the elevator door, at a speed of 1.5 feet per second.
Destination-Dispatch Systems
Modern destination-dispatch systems, where users select their floor before entering the cab, can improve efficiency but must be designed with accessible interfaces including tactile, audible, and visual feedback.
Platform Lifts
Platform lifts (also called wheelchair lifts) are used where a full elevator is impractical, such as in existing buildings with limited space, stages, or raised platforms. The ADA permits platform lifts in specific situations, including performance areas, courtrooms, and existing buildings where installing an elevator is technically infeasible.
Design Considerations
- Minimum platform size: 30 inches by 48 inches (ADA minimum clear floor space), though 36 by 54 inches is preferred.
- Maximum travel distance: typically 12 to 14 feet for vertical platform lifts, though this varies by manufacturer and jurisdiction.
- Controls must be operable from the platform and from each landing.
- Enclosures or guardrails are required when the lift rises more than a specified height (often 12 inches, per local code).
Stairs
Even in fully accessible buildings, stairs remain the primary vertical circulation for most ambulatory users. Universal design improves stair safety for everyone.
Tread and Riser Dimensions
Uniform riser heights (between 4 and 7 inches, with 7 inches being the most common maximum) and tread depths (minimum 11 inches) reduce tripping. All risers and treads in a flight must be uniform.
Handrails
Handrails must be provided on both sides of all stairs, at a height of 34 to 38 inches measured from the stair nosing. They must be continuous along the full length of the stairs and extend 12 inches beyond the top riser and one tread depth beyond the bottom riser.
Visual Contrast
A contrasting color strip on the leading edge of each tread (nosing) helps people with low vision identify the edge. This small addition prevents a significant number of stair falls.
Open Risers
Open risers (stairs with gaps between treads) are not permitted on accessible routes because they create a tripping and catching hazard, particularly for users with prosthetics or braces.
Choosing the Right Solution
| Situation | Recommended Solution |
|---|---|
| Elevation change under 6 inches | Beveled threshold or short ramp (no handrails required) |
| Elevation change 6 to 30 inches | Ramp with handrails and landings |
| Elevation change over 30 inches, new construction | Passenger elevator |
| Elevation change over 30 inches, existing building with space constraints | Platform lift (where code permits) |
| Temporary access need (construction, events) | Portable ramp or temporary lift |
Integration with Building Design
The best vertical circulation systems do not feel like accommodations. They are integrated into the architecture.
- Ramps can be designed as landscape features, incorporating planters, seating walls, and gentle curves.
- Elevators placed at the main circulation core, rather than hidden in a back corridor, signal that accessibility is a priority.
- Stairs with excellent lighting, clear handrails, and visual contrast serve all users better.
Key Takeaways
- ADA requires a maximum ramp slope of 1:12, with handrails on both sides and level landings every 30 inches of rise.
- Elevators must meet minimum cab size, control placement, and door timing requirements under ADA and ICC A117.1.
- Platform lifts are permitted in specific situations where a full elevator is not feasible.
- Stairs in universally designed buildings include handrails on both sides, uniform dimensions, visual contrast at nosings, and closed risers.
- The most successful designs integrate vertical circulation as a seamless part of the architecture, not an afterthought.
For the full framework, see the Universal Design in Buildings and Architecture Guide. For entrance-level accessibility, see Accessible Parking and Entrance Design.
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: Ramps — U.S. Access Board