The reeling housing market has come to this: To shore it up, two Senators are preparing to introduce a bipartisan bill Thursday that would give residence visas to foreigners who spend at least $500,000 to buy houses in the U.S.

The provision is part of a larger package of immigration measures, co-authored by Sens. Charles Schumer (D., N.Y.) and Mike Lee (R., Utah), designed to spur more foreign investment in the U.S.

Foreigners have accounted for a growing share of home purchases in South Florida, Southern California, Arizona and other hard-hit markets. Chinese and Canadian buyers, among others, are taking advantage not only of big declines in U.S. home prices and reduced competition from Americans but also of favorable foreign exchange rates.

To fuel this demand, the proposed measure would offer visas to any foreigner making a cash investment of at least $500,000 on residential real-estate—a single-family house, condo or townhouse. Applicants can spend the entire amount on one house or spend as little as $250,000 on a residence and invest the rest in other residential real estate, which can be rented out.

"This is a way to create more demand without costing the federal government a nickel," Sen. Schumer said in an interview.

Foreigners immigrating to the U.S. with the new visa wouldn"t be able to work here unless they obtained a regular work visa through the normal process. They"d be allowed to bring a spouse and any children under the age of 18 but they wouldn"t be able to stay in the country legally on the new visa once they sold their properties.

The provision would create visas that are separate from current programs so as to not displace anyone waiting for other visas. There would be no cap on the home-buyer visa program.

Over the past year, Canadians accounted for one quarter of foreign home buyers, and buyers from China, Mexico, Great Britain, and India accounted for another quarter, according to the National Association of Realtors.

The idea has some high-profile supporters, including Warren Buffett, who this summer floated the idea of encouraging more "rich immigrants" to buy homes.