A significant shortage of affordable housing options is fueling America's affordability crisis, particularly for those looking to move out on their own for the first time, a new Zillow analysis shows. This huge housing deficit underscores the need for policies and investments that can boost construction.

This lack of housing — especially affordable options — has left millions of households "missing." These missing households consist mainly of individuals and families living in another family's owned or rented home. Across the country in 2021¹, there were nearly 8 million missing households, compared to just 3.7 million housing units available for rent or sale, a deficit of 4.3 million homes.

"The U.S. housing market is like a high-stakes version of the game musical chairs," said Orphe Divounguy, senior economist at Zillow. "There are simply not enough homes for millions of people. Unless we address the shortage of smaller, more-affordable, starter-type homes, we risk leaving families without a seat — and it will only get worse over time."

For each of the 3.7 million housing units available for rent or sale across the country in 2021, there were more than two potential households — families likely in need of their own homes. This means even if every missing household was willing and able to move into their own home, 4.3 million households would have been left without a place to move to.

The bulk of families doubling up have consistently lower incomes, highlighting the need for smaller, more affordable housing. Of the families that are doubling up, 68% had an annual income of $35,000 or less.

The mismatch between potential housing needs and available homes across the country is playing out in dramatic fashion in the most expensive coastal housing markets, such as Los Angeles, San Francisco, San Jose, San Diego and Boston but also in places like Boise.

What consumers need to know
Zillow has a number of tools and partnerships to help consumers overcome these challenges.

Zillow's affordability calculator and monthly payment filter can help shoppers better understand how much they can afford and how best to find an affordable mortgage payment. Working with a trusted real estate partner is also critical to helping find an affordable home for new buyers.

All home listings on Zillow display available programs that help eligible shoppers with a down payment — the biggest barrier to homeownership for most. This first-of-its-kind tool was used by more than 1 million customers in just its first year, with the average recipient qualifying for $17,000 towards a down payment.

And for renters, Zillow offers a single, flat-fee rental application tool that helps would-be-tenants avoid paying hundreds of dollars in application fees, which can quickly become a financial hardship for low-income families.

What policymakers can do
Construction productivity has been declining relative to the rest of the U.S. economy since the late 1960s, with land-use restrictions, building approval delays, and stunted construction sector growth all contributing to the lack of new home construction across the country. Policymakers should explore ways to boost production and overall growth of the construction sector to ensure housing supply can catch up to demand.

Additionally, experts are near unanimous that loosening restrictive zoning laws is critical to creating more supply and easing housing costs. According to public polling conducted by Zillow, four out of five adults support allowing more, smaller home types to be built in their own neighborhoods. Researchers also suggest that speeding up building permitting, eliminating parking requirements, tax incentives to rehabilitate underutilized housing stock, and expanding affordable housing trust funds could all help ease the shortfall in new construction.

Sources and Methodology
This study uses the American Community Survey to provide a simple count of the number of families living in other families' housing units. The number of families that do not currently own a home is estimated from IPUMS USA by counting each family in each household using the FAMUNIT variable and the appropriate weights. There can be multiple families either living in rented households or living in owner-occupied homes. To estimate the housing unit deficit, we compare families that were living in another family's home with the number of units for sale or for rent across the country in the same time period.