After reading this topic now I understanding more of Stairs and Egress. when we talk about strairs and egress we must mentions : Building codes that have some requirements for when considering the safety exits and paths in the building. for emergency this gives all patrons a safe exit and path. even though stairs and egress can prevents the spread of fires, which can cause more damage to the structure. Stairs are so much important in buildings design and structure. all the desinger must take care a do perfect the stairs. The most important requirements are set for the min and max risers and trends. after reading this I will never forget that landings should be as wide as the stairs widths.