But Lautz didn’t know that housing affordability experts at the Federal Reserve Bank of Minneapolis were working on the same issue.

Last week, researchers at the Minneapolis Fed led by Erik Hembre published research showing that the real under-35 homeownership rate is closer to 22% than the widely cited 37%, when measured by head of households or whether you own the home you live in.

Lautz told Fortune that she’s been circling the same trend in her own generational research for months. “I was excited when it came out,” she said. “I had no idea, obviously, but I think it captures the change in how people are living, and it does so in a smart way where it’s really looking at who’s in that household as opposed to the structure of that home.” When she really digs into the data, she added, she sees younger Americans under 35 years old being pushed toward a housing arrangement not seen at scale in America for more than a century.

Two cohorts, two economies

NAR now splits millennial data into two groups—ages 36 to 45, and ages 27 to 35—because the gap between them had grown too wide to report as a single number. Lautz called it a “definite split” in April, because older millennials have become the highest-earning, biggest-spending buyer segment in the entire housing market.

Their median household income is $132,700. They’re buying the largest homes of any generation at a median 2,100 square feet, and only 33% are first-time buyers, meaning most already own and are leveraging equity to trade up, running the same playbook boomers used for decades.

Younger millennials are still fighting the battle their older counterparts just won, and the numbers show how wide the gap has gotten. They’re buying 1,600-square-foot homes, a 500-square-foot gap from their older peers. Their median down payment is 9%, compared to 13% for older millennials, 19% for Gen X, and 26% or more for boomers, meaning the equity flywheel that lets older buyers keep trading up is barely turning for the younger cohort. Forty-four percent of younger millennials who struggled to save said student loans delayed their purchase; high rent held back 42%; credit card debt, 30%. It’s a three-way squeeze that older millennials largely escaped by buying earlier.

The Minneapolis Fed research underscores not only “how difficult housing affordability is,” Lautz said, “but also how difficult high rents can be in many communities.” It shows that while people may want to live independently, they may be forced to make the choice illustrated in Hembre’s research. But she went further in describing the younger cohort’s predicament—not as a temporary delay but as a reversion to a much older pattern.

Younger millennials, meet 1900

The NAR data shows clearly that more families double up during times of unaffordability, Lautz said, citing the housing bust of 2008. It’s something that is clear to see in the data today as well, with one counterintuitive wrinkle: It’s Gen X, not younger millennials, buying multigenerational homes at the highest rate (19% vs. 9% for younger millennials). That gap makes sense once you realize the Hembre research is capturing something the NAR data can’t: the young adults who live in those multigenerational households without being the purchaser. When younger millennials do buy multigenerational homes, the NAR data shows cost savings is the driver for 55% of them—far higher than any other generation, and a telling sign of who’s making this choice by financial necessity rather than family preference.

When asked whether this means America’s housing market is turning more European or Asian, where multigenerational homebuying is more common, Lautz said, “Absolutely.” Describing it as “an older way of living,” she said it’s “bringing us back, perhaps, to the early 1900s,” where data shows families doubled up at higher rates based on the availability and cost of housing.

The multigenerational shift Lautz describes isn’t a story about idle young adults. According to Realtor.com’s latest research, a record 25.2 million adults under 35 lived with their parents in 2025, nearly one in three, a rate that has now surpassed even the pandemic-era peak. Roughly 70% of them are employed, and many hold college degrees. This isn’t a generation avoiding work; it’s a generation working full paychecks that still can’t clear the cost of independent housing, driven largely by a national median home listing price of $430,000—34.4% above 2019 levels—and asking rents nearly 18% above pre-pandemic norms.

The trajectory is what makes the moment historic. In 2014, Pew Research documented a genuine milestone: For the first time in more than 130 years, American adults ages 18 to 34 were more likely to live with a parent than with a spouse or partner in their own household, a turn of events “fueled primarily by the dramatic drop in the share of young Americans who are choosing to settle down romantically before age 35.” Of course, that’s a chicken-or-the-egg question that defines much of modern economics, culture, and even society: Is the extended adolescence that reaches out to 35 because of changing behaviors around marriage and homebuying, or do those reflect the fact that they’re not affordable until 15 years into one’s career?

The boomer silver lining

Lautz did not put a purely negative framing on the current state of generational housing economics, including the fact that boomers appear to be using their wealth advantage to upsize. Boomers between 61 and 70 sell a median 2,000-square-foot home and buy a median 2,000-square-foot home. Net change: zero. Boomers between 71 and 79 downsize by just 100 square feet. Meaningful downsizing appears only among sellers 80 and older—and even they only give back 300 square feet.

“They want to hold on to their space,” Lautz said, “and that could be [that] they like their things [or] they want to host their families at the holidays.” The modern life span, with boomers living decades into their retirement and facing huge expenses if they move into retirement homes, is a “huge contributor” to this dynamic, she added, along with the fact that many boomers are working into a later age. The data also indicates that some boomers are recognizing their children and grandchildren’s affordability struggles and purchasing multigenerational homes, she added.

To be sure, she clarified, the “sandwich generation” of Gen X—caught between aging parents and dependent children—is the largest purchasers of multigenerational homes, and many older millennials are beginning to, as well. “They’re hitting their forties, and older millennials may have aging parents that they need to take care of in that situation.”

Lautz isn’t entirely pessimistic. Gen Z’s homeownership rate is running slightly ahead of where millennials stood at the same age, something she attributes partly to stronger uptake of government homebuying assistance programs. “I am encouraged by looking at that data,” she said. But she stopped short of predicting the pattern breaks for Gen Z on its own.

“It’s not going to be an overnight [fix where] we flip the switch and we’re going to see a different housing market tomorrow,” Lautz said. Building enough smaller, more affordable housing will take roughly a decade, and an aging boomer population eventually vacating larger homes “is not the solution” on its own, she said.

The generational label “millennial” now obscures more than it reveals. The real story isn’t one generation lagging behind or catching up. It’s a fault line running through the middle of it—one side building wealth on equity and square footage, the other moving back in with family in a pattern their great-grandparents would have found unremarkable.