Factors beyond high mortgage rates are affecting housing affordability for many Americans, according to experts.

Almost four years ago, a household earning $59,000 annually could afford a new mortgage without spending more than 30% of their monthly income and with a 10% down payment, according to a recent report by Zillow Group.

That is no longer the case today.

While the typical household in 2024 makes about $81,000 a year, up from $66,000 in 2020, wages have not kept up with housing costs.

"Since January of 2020, the typical mortgage payment on the typical home in the U.S. has nearly doubled," said Orphe Divounguy, a senior economist at Zillow.

Nowadays, potential homebuyers need to make about $106,500 a year in order to afford the typical home today, an 80% increase from January 2020, according to Zillow.

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The connection between housing costs and wages has been gradually separating over the years, according to C. Kirabo Jackson, an economist and member of the White House Council of Economic Advisers.

"Around the mid-'90s, you start to see housing prices sort of separate from median wages in a way that kind of made housing less and less affordable for people who are in the market," Jackson said.

More supply 'helps keep prices down'

Tight supply is another reason behind unaffordability. Fewer homes available on the market for would-be buyers keeps real estate prices elevated and, in some local markets, the shortage makes prices climb higher.

The number of new housing units built throughout the years has been declining, and the low supply is rooted in restrictive land-use and zoning regulations, according to experts.

"If we have a supply problem, we really need to have a supply solution," Divounguy said.

Land-use and building regulations across the country make it difficult in some markets to build new homes, Divounguy said.

And the most important way to improve affordability is to construct more housing in the U.S, he said.

To increase housing supply, local policymakers would need to lower the barriers for builders by easing land-use and zoning regulations, which determine factors like the maximum height of a building or the minimum size of a lot, Jackson said.

For example: Some local areas may say you can't construct buildings more than three stories high in a particular area, which means high-rise buildings that could house about 100 people are out of the question.

"Instead, you have to have a house that maybe has five people," Jackson said. "The more supply you have helps keep prices down. So the more housing that you make available, the more that's going to sort of ease price pressures."

While increasing the housing density in an area can boost affordability, land-use and zoning regulations, which inherently determines an area's housing supply, is often decided at a local level, he said.

"If you really wanted to expand the supply of housing, one of the most immediate ways one could do that would be to ease up on these zoning restrictions and allow the construction of affordable housing in areas that currently would not be allowed under local land-use rules," Jackson said.

Some areas have already begun to see a boom in new housing inventory due to relaxed zoning rules, according to Divounguy. Markets that allow builders to make smaller, attached homes as opposed to detached, single-family housing are seeing a surge in new construction, like markets in the South.

"Markets that have more restrictive land-use, regulations, zoning rules are markets where you're not seeing the type of new construction necessary to keep up with demand for housing," Divounguy said.

While local zoning rules are not under the federal government's control, the administration is working toward local areas to be more flexible by providing financial incentives to help developers build more affordable housing, said Jackson.

"We have a growing economy, we have a growing population. As your population grows, you have to build more housing to accommodate the growth and population," Jackson said.