Even before the pandemic, the number of adults living with their parents was high after the last financial crisis, as millennials flocked to the basements and spare bedrooms of Baby Boomers.

"Now, it's Gen Z's turn to ride out today's crisis amid massive unemployment," Zillow Senior Principal Economist Skylar Olsen, was quoted as saying. "But this time, rents are more likely to slow, easing the path to returning to living on their own even if some under-employment persists."

As apartment construction has exceeded "historic norms" in recent years, Olsen said, some young adults are likely to double up or live more affordably in various ways, which should soften rent growth.

Meanwhile, living with parents rent-free, and staying even after jobs return, could allow some Gen Zers to save enough for homeownership more quickly or may even delay their parents from downsizing into a smaller home, Zillow noted.

Cities with a higher share of young renters may see a disproportionate impact. This includes Austin, Kansas City, Cincinnati and Pittsburgh, Zillow said. On the other end are areas with more millennials and older renters, including Miami, New York and Los Angeles, which each have less than 1% of the rental market made up of young people who have moved home, Zillow said.