About 20 percent of the US population has some type of long-lasting condition or disability. The 1990 Americans with Disabilities Act (ADA) prohibits discrimination and guarantees that people with disabilities have the same opportunities as everyone else to participate in the mainstream of American life -- to enjoy employment opportunities, to purchase goods and services, and to participate in state and local government programs and services.
The ADA includes Standards for Accessible Design that outline requirements to facilitate access, mainly for public accommodations and commercial facilities, recreational facilities, streets and sidewalks, and other elements of the built environment. They deal with the need for and dimensions of features such as elevators, ramps, doors and corridor width,
Over the life of a home, it is likely that at least some residents will have limited mobility, at least for periods of time, or will at least have visitors with limited mobility. However, newly constructed homes often contain the same major barriers as older, existing homes: steps at every entrance, and narrow interior doors, with the bathroom door usually the narrowest door in the house.
Visitability features make homes easier for people who develop a mobility impairment to visit friends and extended family rather than having to turn down invitations, or not be invited at all. These features also provide basic access to permit formerly non-disabled people to remain in their homes if they develop a disability, rather than forcing them to do expensive renovations, relocate to a different house, live in an inaccessible home which endangers their health and safety, or move from the community into a nursing home.
All homes, whether or not designated for residents who currently have mobility impairments, should be designed in such a way that they can be lived in or visited by people who have trouble with steps or who use wheelchairs or walkers. This involves three main measures. Providing at least one zero-step entrance on an accessible route leading from a driveway or public sidewalk, making sure that all interior doors provide at least 32 inches of unobstructed passage space and installing at least a half bathroom on the main floor you can get into in a wheelchair.
Two additional measures are recommended to allow residents to remain in the home if mobility impairment occurs: a full bathroom on the main floor, and a bedroom or space that could be converted to a bedroom on the main floor.