A community-based approach to the development of intergenerational housing cooperatives could teach new lessons on how different age groups can benefit from living together. Examples of intergenerational housing cooperatives where elderly people live together with young adults in order to help each other have existed in most European countries for some years now.

Tiffany Tieu, 26, and Laura Berick, 80, formed an unlikely friendship while living at Judson Manor, a retirement community. Judson Manor houses a select group of music students for no charge in exchange for performing recitals and concerts for the older residents. At Judson Manor, age is just a number.

Intergenerational housing aims at strengthening social cohesion and fighting isolation of elderly people and other vulnerable groups. In particular, an effective management of ageing-related risks through housing can have a positive impact on the cost of healthcare policies and the lifestyle of older people. Intergenerational solidarity should be based on the need to rebuild family-like links at the community level in order to fight isolation, loneliness and vulnerability, while respecting the private life of each individual.

All successful examples of community-based projects I found have external support from local authorities or other public organizations, showing the need for public involvement if this model is to be generalized and potentially used in different socio-economic contexts.

The number of Americans living in multigenerational households — defined, generally, as homes with more than one adult generation — rose to 56.8 million in 2012, or about 18.1 percent of the total population, from 46.6 million, or 15.5 percent of the population in 2007, according to the latest data from Pew Research. By comparison, an estimated 28 million, or 12 percent, lived in such households in 1980.