NEW YORK (Money magazine) - A survey of 1,002 homeowners conducted for Sears Roebuck by Matthew Greenwald & Associates backs me up in my contention that too many homeowners are unprepared for the expenses of ownership.

It reports that half of all homeowners never estimate what it will cost to live in a house before buying it.

So whether you're thinking of buying, trading up or just trying to maintain the status quo, what should you do to avoid surprises in the future?

START WITH AN INSPECTION Of course you'll get an inspection if you're buying a new home. (My parents' house passed a termite inspection five years ago when they moved in.)

How much do you need? Ongoing maintenance expenses add to the cost of home ownership. Item  Life   Cost  Set-aside  Roof  10 yrs  $2,524  $21.00 /month  HVAC  13  5,461  $35.00  Refrigerator  6  820  $11.39  Oven  6  984  $13.66  Washer  8  591  $6.16  Dryer  8  535  $5.57  Exterior paint  6  4,100  $56.94  Windows  15  15,002  $83.34  Doors  15  6,876  $38.20  Driveway  9  4,802  $44.46  Heater  8  1,013  $10.56   Source:  Askthebuilder.com

You should walk through with the inspector -- to find one, go to the website of the American Society of Home Inspectors at ashi.org -- as he or she looks at all of the major systems in your home, from the roof to the appliances. You'll come out with a road map of what you'll need to replace or repair and a rough timetable for when the work will have to be done.

Once you've been in the house 10 years, spending $500 or so for a repeat inspection will let you know what lies ahead.

BUDGET FOR MAINTENANCE According to Kermit Baker, senior research fellow at Harvard University's Joint Center for Housing Studies, you should plan on spending 1percent of the value of your house (minus the value of the land) on annual maintenance.

If you recently spent $400,000 on your house and it's sitting on a $100,000 lot, you're looking at $3,000 a year. But, notes former contractor Tim Carter, who runs the Ask thebuilder.com Web site, what you have to realize is that the number accrues. If you haven't put any money into your house for, say, five years, you can be pretty sure that a $15,000 maintenance bill is around the corner. That's why he suggests making regular deposits into a "sinking fund," an accountant's term for a pool of money you'll use for future expenses.

Mark Zandi, chief economist at Economy.com, notes that the cost of making household repairs has been outpacing inflation (often by as much as one-third) for the past five years. So raise the amount you're depositing into the sinking fund each year to keep pace with those increased costs and the rising value of your house.

DO IT NOW--AND DO IT RIGHT Letting a problem fester is likely to cost you significantly more in the long run.

Take the urethane coating on your hardwood floors. Putting on a new coat once every 18 months will cost pennies a square foot. But if you wait until you've worn the coating down to the floor, then you have to sand the floor completely and apply four to five coats of urethane at a cost of dollars a square foot.

Pay to have the job done right. There's nothing more frustrating than having to redo a shoddy job a year down the road. Well, maybe not nothing. You could have termites.

Editor-at-large Jean Chatzky also appears regularly on NBC's "Today." Contact her by e-mail at moneytalk@moneymail.com.