Sara Jane and Michael Treinen know a thing or two about home improvement, and their story-and-a-half Cape Cod in Des Moines, Iowa, shows it. In the 25 years they've owned their home, it's seen a steady stream of contractors who've tackled everything from kitchen and bath redos to new decks (two of them), new windows, new siding and a sunroom addition. Factor in mundane maintenance, such as roof and driveway replacement, and the paint-and-paper projects the Treinens have tackled themselves, and it's no wonder they estimate their home's current value at roughly triple what they paid for it.

But resale value never was uppermost in the Treinens' minds. They knew early on that they were there for the long haul, so they remodeled "just for the pleasure of living in the new space," as Sara Jane puts it. When one of their contractors inquired, "Why don't you sell this house and let me build you a retirement home?" her reply was short and sweet: "This is it!"

Payback Time

If you're less sure how long you'll be staying put, recouping maximum value for your improvement dollars becomes more important. That's why, for the past 16 years, Remodeling magazine each November has published its annual "Cost vs. Value Report." Aimed at professional remodeling contractors, it looks at 10 of the most popular home-improvement projects and their recouped cost at resale (under current market conditions) in 35 cities across the country. We've summarized the national averages for 2003 in the chart below, but you can read the entire report online at www.remodelingmagazine.com.

Sal Alfano, the magazine's editor-in-chief and author of the annual report, agrees wholeheartedly with the Treinens' strategy. "How long you plan to stay in the house makes a big difference because remodeling is one of those investments where you can get the use of the money, and there aren't too many like that out there," he says. "With remodeling, you get the use of the new space and then when you finally sell the house, you get the difference in the appreciated value tax-free. It's kind of hard to beat."

Still, he's quick to caution: "If resale value is your No. 1 concern, go talk to a Realtor who knows your neighborhood."

Although the report's numbers are statistically valid on a nationwide basis, many variables come into play when you zero in on individual cities and neighborhoods. "When people are looking for specific information about their neighborhood, they need to look and see what's happening across the street and a few blocks over," he says. "That's going to be the strongest influence, and that changes rapidly."

When Bigger Isn't Better

"You never want to have the best house in the neighborhood," Alfano cautions. It may make you puff with pride -- until it's time to sell and you realize that you'll recoup only a fraction of your remodeling investment.

So are there any can't-miss improvement projects out there? "Anything you can do to improve the cosmetic appearance [of your home] will probably help with resale value, and those are generally less expensive projects as well," he says.

When you go beyond the cosmetic, however, it can get tricky. The most serious mistakes homeowners make involve poor architectural or design decisions. "They remuddle," as Alfano likes to say, by adding hulking additions that are out of character with the house and the neighborhood or by relying on do-it-yourself design for a costly room makeover. "If you don't do it right, then every penny you spend is potentially out the window," he says.

The Treinens once came close to making that mistake themselves.