The world is ageing, and Japan is no exception. Japan is the fastest graying society in the world, and a quarter of its population will be over age 65 by 2014. It is inevitable that many older people will experience difficulties in the environment due to capability deterioration. To address these environmental problems, the Japanese Construction Ministry inititated in 1987 a five-year research and development project on design for the ageing society. Design for All Ages was set as the key concept, discarding the traditional idea of “special design for the aged.” It is a clear departure from age segregation that occurs with sheltered housing. Design for All Ages assumes that residents will age in place, and that the dwellings will be able to respond to the changing needs of residents. After all, dwellings are an important component of a person's life, and disability (particularly age-related disability) should not adversely affect people.

During the research and development stages of Design for All ages, we integrated existing knowledge with new ideas derived from experiments. Basic concepts for dwellings that have been adopted include: Safety; accessibility; usability; and affordability. These concepts can be interpreted in terms of design guidelines:

1) Basically flat floor. No door sills, no step differences, unless vitally necessary.

2) Handrail installation at critical places such as stairs, bathroom, toilet, and entrances.

3) Wider corridors and doors.

The final Guidelines were based on the discussions of effectiveness, design and economic feasibility, climatic conditions, and cultural tradition. However, simply issuing guidelines does not ensure they will be put into practice. Japan has a strong mechanism for implementation: the Japan Housing Loan Corporation (HLC). The HLC has given prospective clients lower interest rates for housing mortgages, and has been a driving force of economic growth since its establishment in 1950. The Corporation took a decisive step in 1996 in establishing barrier-free or energy conscious design to be eligible for lowest interest rates. Along with the Guidelines, consumer education was provided through various approaches. As a result, construction of barrier-free dwellings increased, and the majority of newer dwellings were built to be basically barrier-free.

Older dwellings were and still are poor in terms of barrier-free design. In addition, aged persons who are more vulnerable and experiencing difficulties in daily living tend to live in problematic dwellings with many barriers. To address these problems, the Japan Housing Finance Agency (the successor to HLC) assists with remodelling of older people's dwelling, though most government subsidized mortgages have been discontinued.