Here are five typical projects included in the survey, along with advice from Long Island real estate experts and other professionals. While projects tend to recoup less than 100 percent of the money invested when the home is sold, experts point out that projects like these can mean the difference between a timely sale and a home that lingers on the market.

NOTE: Project totals and descriptions come from Remodeling magazine, which calculated the costs based on the price of labor and materials in the mid-Atlantic region of the country.

DECK

Project: Add a 16-by-20-foot deck supported by 4-by-4 posts on concrete piers. Include a built-in bench and planter, three-step stairway and railing with posts and balusters.

Cost: $10,676

Amount recouped on resale: 83 percent

What the experts say: Surprisingly, although a deck is one of the cheapest home- improvement projects, a number of Long Island real estate agents are of the opinion that it's often not worth the effort. "If a deck is old or rotting, you're better off just tearing it down," says Mark Malsky, owner of Babylon-based RE/MAX Signature Real Estate. "No deck is just as good as a new deck, even if everyone else in the neighborhood has a deck. Most buyers can imagine what a deck would look like and cost."

SIDING

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Project: Replace 1,250 square feet of existing siding with new fiber-cement siding - a more upscale and durable siding. It should be factory- primed and -painted. Include all 4/4 and 5/4 trim, using either fiber-cement boards or cellular PVC.

Cost: $13,359

Amount recouped on resale: 86 percent

What the experts say: This kind of project falls squarely in the realm of curb appeal - the kind of project every real estate agent tends to favor. Outdated - or, worse, damaged - siding can be a liability from the moment the buyer sets eyes on the home. This is where it's worth spending money and, comparatively, the price of the project is still on the low end. With painting, siding is "the No. 1 place to make an improvement for a sale," says Dottie Herman, president and chief executive of Prudential Douglas Elliman Real Estate.

WINDOWS

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Project: Replace 10 3-by-5-foot double-hung windows with insulated, vinyl windows.

Cost: $11,083

Amount recouped on resale: 77.8 percent

What the experts say: Windows are like siding - extremely important in first impressions. As a prime curb-appeal project, they return a high rate on dollars spent. "What you notice first is usually the impression that lasts," says Hofstra's Robert Campbell, who teaches real estate. "Windows are always important."

BATHROOM

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Project: Add a new bathroom - in Remodeling magazine's example, it is 6 by 8 feet. Include a marble vanity top with molded sink; standard chrome faucets; fiberglass tub/shower with ceramic tile surrounding.

Cost: $40,290

Amount recouped on resale: 55.4 percent

What the experts say: The return on investment numbers here is not great, but local experts suggest you not base your decision on numbers alone. "It's like trying to convince someone to continue investing in a stock that is declining in value," says Robert Campbell, who teaches real estate and finance at Hofstra University's Frank G. Zarb School of Business. "Except you already own the home," he says. And spending the money on a project may mean the difference between a quick sale and a home that lingers on the market for many months. So those who look at just the numbers to calculate a return are probably missing the point, he says.

KITCHEN

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Project: Update kitchen - in Remodeling magazine's example, it's 200 square feet - with 30 feet of cabinetry, as well as countertops, sink and faucets. Replace cabinet fronts with new wood doors, and change drawers and hardware. Install new energy-efficient appliances. Replace flooring.

Cost: $21,908

Amount recouped on resale: 77 percent

What the experts say: Dottie Herman, president and chief executive of Prudential Douglas Elliman Real Estate, points out that money spent on renovating kitchens and baths can be crucial. "People notice an outdated bath or kitchen very quickly," she says. "But you don't want to do anything out of the ordinary. " A restrained approach is best. "We recently had to sell a home where the seller had just built her dream kitchen. What she didn't realize was that her favorite yellow was not to everyone's liking," Herman says.