As people live longer and desire independence over aged-care facilities, they prefer to remain in the homes they own. Some 60% of free-standing houses with back yards are occupied by people over 50, and in greater Melbourne alone there are 30,777 lone-person houses with two or more bedrooms occupied by people over 70. This creates social dilemmas for the old and the young, and we are in need of strategic thinking and creative solutions to address the facts.

Our housing crisis is acute: a 2016 report for the Population Research Institute by Bob Birrell and David McCloskey stated that Melbourne will need an extra 355,000 homes by 2022. Sydney will need an extra 309,000. But calling on older households to downsize will not solve the problem. Older homeowners often prefer to stay put, with good reason: many are happy where they are, in familiar surroundings. Of those who might consider moving to a smaller property, many are deterred by the costs of renovation, agents, surveyor and legal fees, and the pernicious stamp duty payable on a new property. Accessing capital can also mean the loss of a pension, leaving those who do move financially worse off in a smaller house.

Financial problems are a real concern for many older people: some 35.5% of people over the age of 60 in Australia are defined as living in poverty, unable to find work or to access the pension. Public housing spaces have declined over the last decade, and support costs are rising: estimates are that it will cost $214m million in one year to pay for people older than 65 who are eligible for the National Disability Insurance Scheme.

Even if living alone by choice, older people need company, support, places to go, and the means to get there. We know that older adults’ health and wellbeing improve when they have varied opportunities to stay socially engaged as part of a familiar community. To achieve successful longevity we need to adapt.

Meanwhile, today’s younger generation, unable to buy into the high-priced housing market, is also making adjustments: they are having to live with their parents longer, sometimes conducting relationships under the same roof as they remain in study, work and save, and search for a job. More are deciding they won’t marry, nor will they have children: in 1976, 67% of 24 year olds were married, but in 2011, that figure had fallen to only 14%. By 2031 it is predicted the proportion of families in Australia with children (38 %) will be overtaken by couples without children (43%). Lone-person households are forecast to increase by 73% to constitute some 3.2 million households.

The time has come for multi-generational living. There has already been a shift toward such housing arrangements over the past three decades as marriage demographics have changed. Renovations on the family home are adding bathrooms and living space, and increasingly grandma or grandpa is joining in (if their house is not the family home already).

Alongside living changes involving multi-generational families, there are ingenious models for intergenerational living cropping up around the globe under the umbrella of Homeshare. This movement has its roots in the USA and the idea is spreading: Australia is now part of this movement for innovation in inter-generational living.

Share arrangements can be flexible, and are all about finding the right match. Program coordinators screen all applicants, suggest matches and either refer one person to another, or support people to choose a suitable match. In some cases, low-income singles can be offered rent-free homes with senior citizens in return for help with daily chores. Homeshare also has potential in the delivery of services to those with disabilities, with offers of housing assistance being made in exchange for practical support.

Given that housing our population – the old and the young – has become such a contentious challenge, we should look closely at innovations like Homeshare. We may well discover that it will service mutual needs successfully, and help maintain the neighbourhood connections that sustain us all.

Patricia Edgar is the author of In Praise of Ageing (2013), PEAK, Reinventing Middle Age (with Don Edgar, 2017), and an Ambassador for NARI, The National Ageing Research Institute.