With too few skilled laborers to meet the growing demand, construction is taking longer, costs are rising, and, as a result, the much-needed housing supply in the U.S. remains constrained.

Experts in the industry point to an aging workforce, a lack of younger Americans entering the skilled trades, and immigration policies that they say have failed to keep pace with labor needs.

“Labor is one of the largest and most expensive inputs when it comes to home production and land development,” Jim Tobin, president and CEO of the National Association of Home Builders, told Fox News Digital.

He said that every month, the construction industry is short by approximately 250,000 workers.

“It’s been as high as 400,000 jobs short when we were really cooking along a few years ago,” Tobin said, adding that the labor gap “is a persistent shortage.”

And the industry’s labor needs are only expected to grow in the coming years.

A recent Home Builders Institute and National Association of Home Builders report estimates builders will need roughly 723,000 new workers annually to keep pace with demand and help close the nation’s 1.5 million-home housing gap.

The shortage is already affecting how quickly homes can be built. According to Home Builders Institute President and CEO Ed Brady, labor constraints are extending construction timelines and driving up costs.

“This shortage adds nearly two extra months to building timelines, inflating costs and delaying delivery,” Brady told Fox News Digital.

Builders say replenishing the skilled trades pipeline is only part of the solution.

While builders continue to invest in workforce development programs and encourage more young Americans to enter the skilled trades, Tobin argued for immigration reform measures that he says will benefit the industry.

“It’s not only about training more people to come into the industry as our current generation ages out of the skilled trades, but it’s also the immigration problem that we have in this country,” he said.

Tobin said many construction jobs do not require a four-year college degree and can provide stable, middle-class careers, but the home construction industry has struggled for years to attract enough workers to replace retiring tradespeople.

At the same time, builders have become increasingly reliant on immigrant labor. According to the National Association of Home Builders, immigrants account for roughly one-third of the homebuilding contractor workforce.

Tobin called on lawmakers to modernize the nation’s immigration system, including creating legal pathways for workers already in the country and expanding visa opportunities for those seeking construction jobs.

“We’ve got to find a way to modernize our immigration laws,” Tobin said. “We’ve got to create a visa system for people who want to work legally in this country, in the construction industry.”

Without additional workers entering the labor force, Tobin said, builders will continue to face challenges meeting housing demand and bringing more homes to market.