Not every private building is handicap accessible. Handicapped is a person who has a physical disability that doesn't allow him to do most of the "normal" things such as walking, running, etc without the help of any kind of tool.
During the last years to avoid people with disabilities to be discriminated and to protect their rights and dignity, the United Nations General Assembly made the Convention of the Rights of Persons with Disability in 2006. This Convention is aimed to protect, promote and ensure the full enjoyment of human rights by persons with disabilities.
Disabled people have the right to access to social, economic and political life not only a physical access but access to tools, services and facilities for which everyone pays.
The Convention states that all the public offices and the main services (such as doctor's ambulatory, pharmacy, hospitals etc) must be Handicap accessible. Being handicap accessible means that public offices must have Braille signage, elevators, wheelchair ramps, walkway contours, audio signal at pedestrian crossings etc.