Crunching the numbers on a refi

Some borrowers may lose money even with a smaller monthly payment

Unless you’re a serial refinancer — someone who refinances whenever rates drop 1/4 to 1/2 percent — you may not be aware of the mounds of documentation required to refinance a home. Get ready for a tedious process.

It may be worth the hassle if you can get a 30-year fixed-rate mortgage with an interest rate of less than 4 percent. During the week ending Nov. 21, rates on 30-year fixed-rate conforming mortgages fell to 3.31 percent — a low in Freddie Mac records dating to 1971.