The American dream of homeownership may be shifting gears. Single-family homes built for rent are popping up across the country at record rates. This new trend, known as built-to-rent, is primarily concentrated in major metros like Phoenix and Atlanta but is spreading to all regions.

According to the National Association of Home Builders (NAHB), construction of 18,000 single-family built-for-rent homes started in the first quarter, a 20% spike over the same time a year ago.

Don't Miss:

• If there was a new fund backed by Jeff Bezos offering a 7-9% target yield with monthly dividends would you invest in it?
• Elon Musk has reportedly bought 6,000 acres of land just outside of this city. Here’s how to invest in its growth before he floods it with new tech workers.

"When mortgage rates move higher, and it's harder to buy a home, renting becomes more of an option," NAHB Chief Economist Robert Dietz told CNBC.

Built-for-rent communities are clusters of single-family rental homes in a professionally managed community with amenities such as swimming pools, tennis courts and dog parks. With no maintenance costs, homeowners association fees, or mortgage payments, built-for-rents have become a more economical alternative to homeownership that still gives young families the space they need to grow.

"People who can't afford to buy in today's high-priced housing market are opting to rent single-family homes instead," National Association of Realtors Deputy Chief

Economist Jessica Lautz said.

Trending: This real estate fund backed by Uber CEO Dara Khosrowshahi gives you instant access to a portfolio of rental properties, and you only need $100 to get started.

"We are seeing this growing move towards having built-for-rent properties in the U.S.," Lautz said. "[Young adults] have to turn to rental properties because there is no alternative."

According to Zillow, the asking rent for single-family homes in May was $2,262, up 0.5% month over month and 4.7% from last year. Renting an apartment in a multifamily building was less expensive at $1,896, up 2.6% during the same period.

Although the national median mortgage payment, at $2,256, was less than renting a single-family home, homeowners must also pay for costs that aren't figured into a mortgage payment, such as maintenance, repairs, taxes, and insurance.

Last year, builders delivered about 97,000 built-to-rent homes — including those outside built-to-rent communities. That was up 45% from the year before and a record for the sector, according to John Burns Research and Consulting, which provides data on the housing industry.

In almost 90% of U.S. counties, renting is more affordable than owning a home, according to real estate research firm ATTOM.

"For many, renting is just the only affordable option," Susan Wachter, a real estate professor at the University of Pennsylvania's Wharton School, told USA Today.

Keep Reading: