Very tall buildings have several unique characteristics that increase the severity of potential fire events including higher occupancy, longer evacuation times, access issues for responders and potential water pressure/availability issues. Because of these potential obstacles, integrating adequate smoke control systems during the design process is essential.
In multi-story buildings, elevator shafts can act like chimneys as they enable large amounts of air to move from floor to floor. Just as they enable the movement of air, elevator shafts can also transport smoke throughout a building in the case of a fire.
Historic Buildings are usually grandfathered in when it comes to building codes. Therefore, fire and smoke protection is usually lacking greatly. That being said, if major renovations are planned there will be the expectation to meet current building codes.
Mass transportation is undergoing large surges in growth in large metropolitan areas as the need to connect urban areas with surrounding transit points increases.