Once the damage is done, it can take three to seven years for a score to fully recover. But some lenders are willing to work with borrowers earlier than that.

Mortgage giants Fannie Mae and Freddie Mac, for example, require defaulters to wait five years -- and have a minimum credit score of 680 and put 10 percent down -- before they can purchase a home again. If they don't meet that criteria the wait is seven years, at which point the foreclosure is expunged from a person's credit report.

If defaulters show that extenuating circumstances caused the foreclosure -- such as a health issue that prevented them from working, a layoff, a divorce or other one-time event -- the wait may be reduced to three years.

The Federal Housing Administration allows banks to issue FHA-insured loans to borrowers three years after a foreclosure or a short sale in which the borrower was in default.

Tony and Ginger Read, who live with their three kids outside of Boise, Idaho, took four years to rebuild their credit after they sold their home in a 2008 short sale. Tony had been laid off and the couple had already sold their camper and other valuables in a fruitless effort to keep their home. Eventually, a broker convinced them to sell.

"It was the hardest thing we ever had to do but we couldn't afford the payments," said Ginger.

Tony now has a job supervising a sand and water pumping crew for the fracking industry and the couple's credit score has regained more than half of what it lost.

In January, they were approved for a 4 percent interest FHA loan on a $280,000 house in Fruitvale, Idaho. They close April 12.

Mike Edgar, the broker who worked with the Reads to sell their home and buy a new one, has worked with several clients to help them repair their credit and, when they're ready, buy new homes.

In 2012, he worked with 15 "boomerang" buyers, about a quarter of his sales. He expects that number to double in 2013.