Stairs are always unique design opportunities as they are integral to how we move through & perceive space; as such, always consider:

• • The comfort of the stair riser-run relationship
  • The speed of movement suggested by stair design
  • Detailing of treads, rails, & cheek-walls to provide aesthetic integration, comfort, & ease of use

Simultaneously, stairs are often barriers to universal access in the spaces we create; as such, always consider:

• • Local building codes for best practices for layout & detailing
  • When in doubt, err on the side of ease-of-use

There is wide flexibility in the design of stairs, but steps that comply with accessibility standards should generally be designed within the following criteria:

• • Tread lengths of at least 12" [ 300mm ]
  • Treads with approximately 1% to 2% slope for drainage
  • Well-marked risers [ visual + textural ]
  • Risers between 3" [ 75mm ] & 7" [ 175mm ]
  • Avoid open risers [tripping hazards]
  • Landings at least 5' [ 1.5m ] long
  • Landings whenever there are 12 or more risers required

Always verify with local building codes

As with any circulation design, stairs are integral to how we experience a site. The comfort of the user is important; as such, always consider:

• • With which foot the user enters and exits a set of stairs [ to allow for an intuitive flow ]
  • Length of the human stride [ approximately 2.5' or 0.75m ]
  • Height of user [ where their eye level is in relation to the height of the stairs ]

User experience considerations for stairs. Adapted from Astrid Zimmerman's "Constructing Landscape" , 2015.

Link to useful GH scripts & Rhino files