Empty-nest baby boomers own nearly 3 in 10 (28.2 percent) large U.S. homes. That’s twice as many as millennials with kids, who own just 14.2 percent of the country’s large homes, according to a new report from Redfin.

Gen Zers with kids own almost none (0.3 percent) of those properties.

An additional 7.5 percent of the country’s large homes are owned by baby boomers with households of three adults or more; this category likely consists mostly of adult children living with their boomer parents.

The report is based on a Redfin analysis of U.S. Census data from 2022 that breaks down the share of three-bedroom-plus homes owned and occupied by each generation, by household type and size. For the purposes of this report, Redfin used the term “empty nesters” to refer to households headed by baby boomers with one to two adults living in the home.

“There’s unlikely to be a flood of large homes hitting the market anytime soon,” Redfin Senior Economist Sheharyar Bokhari said in a release. “Logically, empty nesters are the most likely group to sell big homes and downsize: they no longer have children living at home and don’t need as much space. The problem for younger families who wish their parents’ generation would list their big homes: boomers don’t have much motivation to sell, financially or otherwise. They typically have low housing costs, and the bulk of boomers are only in their 60s, still young enough that they can take care of themselves and their home without help. Still, some boomers are ready to downsize into a condo or move somewhere new for retirement, and the mortgage-rate lock-in effect is starting to ease, so even though there won’t be a flood of inventory, there will be a trickle.”

It’s worth noting that even though millennials with kids own half as many large homes as empty nesters, there are more millennials than baby boomers. Millennials make up roughly 28 percent of the country’s adult population, the largest share of any generation. They’re followed by baby boomers (27 percent), Gen Xers (25 percent) and Gen Zers (12 percent).

Baby boomers own an outsized share of large homes for several reasons, current and historical.

There’s not much financial incentive to let go of large homes. Most (54 percent) boomers who own homes have no mortgage. For that group, the median monthly cost of owning a home, which includes insurance and property taxes, among other costs, is just $612. For the boomers who do have a mortgage, nearly all have a much lower interest rate than they would if they sold and bought a different home with today’s near-7 percent rates: Even if they downsized, they may have a nearly identical monthly payment.

For millennials and Gen Zers, it’s harder to find and afford a home. Large homes are in short supply, largely due to the mortgage-rate lock-in effect and a recent lack of homebuilding. Large homes are also hard to afford: 2023 was the least affordable homebuying year on record; it was especially hard for younger Americans who don’t have equity from a prior home, Redfin added.

A recent Redfin survey found that 12 percent of millennials who believe they’ll never own a home aren’t interested in homeownership, and 7 percent said they don’t plan to buy because they don’t want to maintain a home.

Many older Americans benefited from an abundance of newly built homes and favorable economic conditions during their prime moneymaking years, during the 1990s economic boom. Those homes proved to be good investments: Home values have grown four times faster than incomes over the last several decades. Today, boomers hold half of the wealth in the U.S., and much of it is in real estate.