A few years ago we showed this image and introduced the "club sandwich generation." This described the phenomenon when people aren't just taking care of their aging parents and their own kids (the sandwich generation), but also supporting grandchildren — a four-generation household. A Pew study at the time showed a dramatic increase in the number of multi-generational households. I wrote:

I cannot find any data about how many four-generation households there are, but I suppose if you're caring for both parents and grandchildren, it will be more convenient and a lot more common. I suspect our houses are going to start looking more like triplexes.

club sandwich When there are too many layers on a club sandwich, it starts to fall apart. (Photo: Erik Forsberg via Wikipedia)

But even the Club Sandwich Generation may soon be competing with an even taller sandwich. Sarah Sands, writing in the Financial Times in a piece titled Five generation families are our future, explains that as people live longer, and more generations get piled on, it's bound to happen.

An economics journalist who has been looking at social care put it neatly to me last week. We are now heading for the five-generation society: 90-something couples with 60-something children, 40-something grandchildren, great grandchildren in their 20s and — yes — great, great grandchildren.

Forget the triplexes, we might have to build apartment buildings for families.

Enter the house designers

Real estate developers and builders are noticing this trend and are designing houses to accommodate multiple generations under one roof. Lennar has a program called Next Gen Living with totally separate suites for the kids or the parents. One popular design has a big apartment with its own connected garage and even its own laundry space; it's two houses in one. It's also vast, all on one floor, and its front facade is pretty much all garage. According to Candace Jackson in the New York Times:

Lennar introduced its Next Gen concept in 2011, during the depths of the recession. Mr. [President and CEO Jon] Jaffe said it was a way to generate interest when the market was slow and buyers needed new ways to help finance their mortgages. It has since become one of the company’s most popular home designs. The number of Next Gen homes built grew 21 percent in 2017 from the prior year, to nearly 1,500 homes, according to Lennar’s latest earnings statement.

Lennar describes their houses as flexible:

Whether you want to use the Next Gen suite as a retreat from the energy of a big, happy family, or want to turn the extra garage into the woodshop you’ve always dreamed of, or need a little extra room for early morning yoga, our options are as flexible as you are.

Yes, but that's just the garage. There is much that's inflexible in the Lennar house, and it's not a great model for the future. In the United Kingdom, the National House Building Council Foundation looked at a prototype home for 2050 with the same ambition: "We will see a resurgence of the 'multigenerational' home, a flexible home where the young can live into adulthood and where the elderly members of the family can be cared for."

adaptable plan Take out the walls and move them around! (Photo: NHBC Foundation)

But they came up with a very different response; they suggest that "homes will be arranged vertically on smaller footprints to increase density and make the best use of limited land." They don't have three garages or even one, because "car ownership will be lower with more journeys taken on public transport, by foot and bicycle, or through the use of on-demand and ride-sharing services." They design the house with clear spans so that rooms can be changed and adapted easily.

This is how a lot of houses were designed a hundred years ago, when lots were smaller because people didn't drive. Town houses often had a stair along one wall and were easily sub-dividable; Many got broken up after World War II to accommodate returning soldiers and many have been turned back into single family dwellings.

toronto house It's a single, double or triple depending on how you use it. (Photo: Lloyd Alter)

Where I live in Toronto, Italian and Portuguese builders with big multigenerational families loved this house design with three levels that could be set up as three apartments, a duplex or a single family house as needed.

Lloyd Alter bedroom The view from our bedroom. (Photo: Craig A. Williams)

I converted my own house into a two-family dwelling and live on the ground floor and lower level, shown here; we are two generations now, but we could well be three in a few years. I doubt that we will make it to five generations, but there's still a garage I can convert to a tiny 250-square-foot accessory unit if I want to someday.

All of this requires a different way of thinking. In many cities, duplexes, triplexes and multifamily homes are illegal under the zoning bylaws. Parking standards often make it impossible to squeeze more units onto a lot. Building flexibility into designs is a bit more expensive.

But as I keep saying, there's a demographic time bomb coming in 10 or 15 years, when the baby boomers get seriously old. When they get into their 80s and 90s, they are going to need every layer of that giant club sandwich for support. That's why these changes have to be made — these kinds of house forms normalized, right now — simply to get ahead of that time bomb.

Lloyd Alter ( @lloydalter ) writes about smart (and dumb) tech with a side of design and a dash of boomer angst.

When you have 5 generations under one roof, the club sandwich metaphor has to grow up
Multi-generation living may get even more multi-generational if current demographic trends — like boomers aging — continue.