A social visit requires the ability to get into the house, to pass through interior doorways, and enter a bathroom to use the toilet.
Temporary disabilities could create a need; for example, a resident could break a leg and require a wheelchair, walker or other mobility device for an extended period.
On new construction, a zero-step entrance can usually be incorporated without an obvious "ramp" per se, i.e., without a structure that has 90-degree dropoffs at the edges and rails at the sides.
Deliberately grading to permit the sidewalk to meet the porch without a step creates access with an invisible modification.
Among these are using a porch as a bridge to the sidewalk; lowering the first-floor rim joist into a notch in the foundation wall at the time of construction; a short, conventional ramp tied into a side or back deck or porch; creative use of a small retaining wall; and constructing the zero-step entrance from the garage.
In the United States, the Visitability movement was begun by grass roots advocates led by Eleanor Smith in an organization called Concrete Change.
The Atlanta chapter of Habitat for Humanity became the first organization to commit to going beyond accessibility in homes with disabled family members.
By including these basic access features in every home built, their commitment contributes to an inclusive neighborhood for people with disabilities.
In 1999, Parliament passed "section M", an amendment to residential building regulations requiring basic access in all new homes.
The AARP Public Policy Institute has produced a report – Increasing Home Access: Designing for Visitability.