According to the Resolution Foundation, the number of two and three-generational households in the UK is around two million. A form of living that was commonplace until the 1950s is being resurrected. I spent my early years in a two-room tenement flat, shared with an elderly grandfather and an unmarried uncle. When we were rehoused in the early 1950s, my uncle came with us. He and I shared a bedroom.

The current housing crisis has provided multi-generational living with new impetus. Shortage and soaring interest rates have created the “Boomerang Generation.” Millions in the 20 to 34 age group are still living with their parents. That can be particularly hard on those used to living independently while at university. On graduation, many find the property ladder way too steep. It’s a double whammy, as renting makes it even tougher to save the all-important deposit.

There’s similar impetus at the other end of the age range. Many baby boomers live in what might be described as “Peter Pan” housing, designed and built on the assumption that occupants never age. Steep stairs and sharp corners may not be a problem at 40, but just wait until you hit 80. An aging population inevitably forces children to face the problem of caring for elderly and possibly frail parents. One possible answer is a variation on the two-generation household. True, that will be seen as a “middle- class solution,” requiring a relatively big house or funds to extend and alter. It’s hardly the answer if you live in a two-bedroom flat.

Nevertheless, the two-generation household might be attractive to those who have serious reservations about care homes. Finding a place can be hard enough without having to worry about the quality of care a loved one might experience. The icing on the cake is the eye-watering cost. In Scotland, the average weekly cost of residential (not nursing) care leaves little change out of £900.

No wonder families look for alternatives such as taking elderly relatives into their own homes. That can preserve capital accruing from savings or sale of their own property. It makes sense to invest in extending and altering your own home rather than drop a small monthly fortune into the pockets of faceless care home owners and shareholders.

Nevertheless, it’s a life-changing event for all concerned and needs to be entered with eyes fully open. While an elderly parent might start off fit and independent, it’s unlikely to stay that way forever. While caring for children generally gets easier as they get older, caring for the elderly becomes more challenging. Having children of your own, adds a layer of complexity, turning your home into a three, not two-generational household.

There are pros and cons. The elderly person will feel more secure and less lonely. They offer reliable and familiar childcare. Costs can be shared, although heating will be more expensive if gran is in the house all day! Some retro-fitting is likely. Are you happy with a stair lift and a walk-in bath? There will relationship issues involving the older person and the younger members of the family. We oldies can be a bit grumpy, especially about noise or choice of TV programme. Most would rather stick a pencil in their eye than sit through Love Island. Spasmodic tension and resentment can arise, depending on who the elderly guest is. It’s only too easy to say, “Do you know what your mum has just done?”

Multigenerational living is back to stay. The National House Building Council (NHBC) estimates an annual requirement for around 125,000 purpose-built, multi-generational homes. NHBC recommends these are designed and built as “lifetime” homes with different generations in mind. That won’t come cheap, but pooling of resources might make it possible. Design must take account of accessibility, private space, and visual and acoustic privacy.

Families must play a larger part in solving the impending elderly care crisis. As far as housing is concerned, a back-to-the-future policy, consciously investing in many more multi-generational homes, might offer at least a partial solution.