As housing, medical, and education costs spiral, new single-family for-sale housing types will appeal as options.

Houses designed intentionally to be multigenerational–accommodating two adult generations of a family household living under one roof–may still be considered a fringe segment of new residential construction.

But for how long?

Pew Research tells us that one in five households in America, 60.6 million people, lived in multigenerational combinations in their homes in 2014, a number that was growing, fast, even post-Recession.

Pew analysts D’Vera Cohn and Jeffrey S. Passel further note that, while adult kids living in parents’ basements (31%) grab the sexy headlines, multigenerational living is a growing choice among aging Americans–more than a fifth live with multiple generations under one roof, including Americans ages 55 to 64 (23% in 2014) and 65 and older (21%).

Two generations ago, up through the time of the Great Depression, multigenerational living was even more common. Almost 60% of households comprised extended families. Now, many of us perceive that extended family living is a cultural choice, more prevalent in Hispanic or Asian families than white households. To some degree, population bears this out. Pew’s analysis notes:

Among U.S. Asians, 28% lived in multigenerational family households in 2014, according to census data. Among Hispanics and blacks, the share in 2014 was 25% for each group. Among U.S. whites, 15% lived with multiple generations of family members.

Think the rate of multigenerational household formation has peaked?

Think again.

Tight supply of for-sale inventory continues to put pressure on prices in more and more economically strong markets. At that same time, aging Baby Boomers are starting to enter their “grandparenting” years in droves. Boomers have tended to remap and remake markets at every turn and life stage as consumers, and among their priorities right now is real-time on-demand access to grandchildren.

It makes sense to us to believe that, for a host of reasons that are only growing more compelling and pervasive–economical, health-wise, culturally, and socially–multigenerational living will get more and more traction, especially since new construction is so hard to bring online and is therefore so expensive. Detroit-based real estate expert Mike Kalis here offers three persuasive reasons builders should put intentionally designed multigenerational living floorplans into the mix of almost every subdivision project.

Here, Trulia economics analyst Cameron Simons spotlights another whole stream of potential for multigenerational households, where two unrelated generations of adults may share a home for economic reasons. Look at today’s household balance sheets and key expenses, and you can see that economic reasons include the Big Three of consumer costs–housing, education, and healthcare.

Simons’ analysis notes big synergistic potential in the fact that many aging Baby Boom homeowners’ houses are replete with extra rooms, while many 20-somethings may be looking to get out from under mom and dad’s roof, but wouldn’t mind being under another mom and dad’s roof. Simons writes about the economic implications:

We looked at the 100 largest housing markets to find people living in homes with at least two bedrooms more than the number of occupants ­– to account for a guest room or office – owned by the oldest Americans. We found tens of thousands of homes have nearly 3.6 million unoccupied rooms that could be rented out.

For retired or soon-to-retire boomers, extra rooms are an opportunity to supplement income and offset cost-of-living increases – as much as an additional $14,000 a year. For many older Americans, renting a room provides an economic boost that may help them stay in a home longer.

For young adults, renting a room as opposed to a one-bedroom apartment could save them up to $24,000 annually.

And that doesn’t even count for intangible values in the arrangement, like companionship, accessibility and connectedness, etc.

Lennar’s home-within-a-home NextGen models broke new ground beyond the double-master-down floorplans that had tended to be adapted by residents into multigenerational living arrangements.

Now, Meritage Homes has partnered with BUILDER, BSB Design, and Intermark Design to push the bounds in exploring nimble, and adaptive multigenerational living arrangements, to suit primary householders with either an older or younger generation of adults living under one roof in a home.

The Meritage reNEWable Living Home aims to serve as a learning and discovery lab for engineering, design, construction workflows, on-going home system operations, and marketing and positioning, that other builders and developers can put to use in their multigenerational product development. We’ll unveil the reNEWable Living Home in January 2018 in Orlando, but you can watch the progress online and start the learning and discovery process here and now at www.builderonline.com/renewable.