Stair design involves creating safe and functional staircases that connect different levels of a building. Key elements include the rise and run of each step, which determine how steep the staircase is. Proper measurements ensure that stairs are comfortable to use and comply with building codes. Materials used in stair design can vary widely, including wood, metal, and concrete. The choice of material affects the staircase's durability and aesthetic appeal. Additionally, features like handrails and landings enhance safety and accessibility, making staircases suitable for all users, including those with mobility challenges.