In fact, while one-year ARMs currently offer tempting introductory rates averaging 5.59%, most experts recommend avoiding them, because you could easily find yourself facing sharply higher payments in the near future, even if interest rates don’t rise. Why? Well, after the introductory rate expires, ARMs are typically pegged to the one-year Treasury rate (recently 5.25%) plus 2.75 percentage points, with increases of as much as two points a year. Assuming interest rates don’t change, you would pay 7.59% in the second year (the full two-point increase) and 8% in the third year.

There are certain cases, however, where an ARM makes sense. If you are fairly certain you’ll be moving within five years, you can save some money — and avoid rising payments — with a five-year ARM, recently averaging 6.62%. Such loans offer a fixed rate for five years and adjust annually thereafter.

The best use for the extra cash is to pay off any higher rate loans you may have. Let’s say that you are carrying a $15,000 car loan at 10% and making minimum payments on a $10,000 credit-card balance at 17%. Your monthly payments on those debts would total $680. Then assume you refinanced your mortgage, taking out an additional $25,000 to pay off your car and credit-card loans. Result: At 7.5%, your additional monthly mortgage payment would total only $175, so you would come out $505 ahead ($680-$175=$505).

Of course, all the extra cash needn’t go for paying off debts. When the Menards swapped their ARM for a fixed-rate last December, they also increased their mortgage load by $34,000, from $106,000 to $140,000. They used $3,000 of the proceeds to pay their refinancing costs and another $17,000 to pay off a 10% home-equity loan, which had been costing them $250 a month. Then they spent the remaining $14,000 to build a garage for Roger’s antique-car collection — and they did all this for just another $19 a month.

Consider Jim Neill, 48, a real estate broker and his wife Merrilyn, 55, a psychotherapist. Recently, the couple took out a 15-year fixed-rate loan at 6.75% to replace an 8.13% ARM with a 30-year term. Their monthly payment jumped by $200, but now they will own their own home outright by the time they retire. In addition, the total interest on the 15-year loan will come to $95,447, vs. $222,234 on the remaining life of the ARM — and that assumes their adjustable rate would have held steady at its current 8.13%. “This is forced savings,” says Jim. “When we retire, we can scale down and take equity out of the house.”

If you can’t afford the payments on a 15-year mortgage, your next best means of building equity is to refinance for less than 30 years. To do so, ask your mortgage company to customize your new loan’s term to match the years that are left on your old loan — if you are five years into a 30-year mortgage, for example, ask for a 25-year loan.

To exploit continued decline in rates, the Barbos refinanced again in December. Their new 30-year fixed mortgage is at 7.375%, lopping another $55 off their monthly bill. Since the couple had chosen a no-cost refinancing each time, their total out-of-pocket expenses came to just $400 in appraisal fees. So by the time you read this, they will already have recouped their up front costs. “Now we can use the savings to build up a cash emergency fund,” says Bob.

If you are considering a second refinancing, don’t overlook this potential tax write-off: When you pay points to refinance, you must deduct the amount over the life of the loan, usually 30 years. But when you refinance a second time, all of the points that have not yet been deducted from the first refinancing can be written off in a lump sum. Say you refinanced to a 30-year mortgage in 1993 and paid $3,000 in points. By now, you would have written off roughly $500. If you refinance again this year, you could deduct the remaining $2,500 on your 1998 tax return. For a homeowner in the 28% tax bracket, that works out to a savings of $700 — enough to offset some or all of your costs this time around.