A vision light is not required in each door opening on an accessible route, but if vision lights are provided for viewing purposes in doors or sidelights, the bottom of at least one of these lights must be located no more than 43 inches above the floor...

Screen doors are sometimes used in commercial or institutional occupancies, where air transfer through the opening is desired. One example of this would be a door leading from a commercial kitchen to the exterior. In some areas of the country where the climate is temperate, this is a common application which consists of two doors in the same opening, one inswinging and one outswinging. It can be very difficult for people with certain disabilities...

A common misconception is that the Fair Housing Act applies only to federally-funded housing projects, but according to the US Department of Housing and Urban Development, “The Fair Housing Act requires all ‘covered multifamily dwellings’ designed and constructed for first occupancy after March 13, 1991 to be accessible to and usable by people with disabilities. Covered multifamily dwellings are all dwelling units in buildings containing four or more units with one or more elevators, and all ground floor units in buildings containing four or more units, without an elevator.”