F.H.A. insurance was created for minority and low-income families who could not come up with the traditional down payment of 20 percent required by private lenders. Buyers receive loans from government-approved lenders and are required to document their income and assets. They must pay a substantial insurance premium of 1.75 percent of the loan. But in return, their down payment can be as low as 3.5 percent.

Image Policy changes in insurance, while introduced on a temporary basis, are becoming so popular that they could prove difficult to undo. Credit... Joe Raedle/Getty Images

For decades, most F.H.A. loans were in low-cost states like Texas and Michigan. Under the agency’s loan limits, houses along the coasts were usually too expensive to qualify. In 2007, fewer than 4,400 F.H.A. loans were made in California, according to the research firm MDA DataQuick, and none were in San Francisco.

The Economic Stimulus Act of 2008 helped change that by temporarily doubling the maximum loan the F.H.A. insured, to $729,750. A two-unit property like the one bought by Mr. Rowland and his friends can be insured for up to $934,200.

“F.H.A. financing was a lost language in San Francisco, the real estate equivalent of Aramaic,” said Michael Ackerman, the agent who represented Mr. Rowland and his friends. “Once the limits were raised, smart buyers started calling.”

The F.H.A. has insured more than 107,000 loans so far this year in the state, according to DataQuick, about 270 of them in San Francisco.

Condominium buildings approved for F.H.A. financing  a relative handful  trumpet the news on their Web sites. The Soma Grand, a new 246-unit building downtown where one-bedrooms cost in excess of $500,000, received F.H.A. certification early in the summer. A half-dozen buyers since then used F.H.A. insurance.

At Guarantee Mortgage Corporation, which has 150 mortgage brokers in the Bay Area, Seattle and Portland, Ore., F.H.A. loans have grown to about 15 percent of its business, from less than 3 percent a few years ago.