By AMY HOAK
Wall Street Journal, Marketwatch

Going to the open house of a home for sale down the block may make you feel like a nosy neighbor. But there are good reasons, beyond sheer curiosity, to take a peek inside.

By knowing the selling prices and how properties look inside, homeowners can become more educated about values in their neighborhood, says Karen Goodman, a real-estate agent with Keller Williams Realty in the St. Louis area.

Attending open houses is especially important if you plan to sell soon. But it’s also a good idea even if you plan to stay in your home for a while. Eventually, these homes will become the competition, and it’s smart to know how your place stacks up, says Ken Shuman, spokesman for Trulia.com, a real-estate website.

“Look at the upgrades they’ve made, look where they haven’t made upgrades,” he says. This exercise helps you “find out where your advantage is and you can focus on that when you put [your house] on the market.” And you’ll know where your home may fall short.

There are other reasons to check out neighborhood open houses:

To prioritize home-improvement projects. Seeing what the neighbors have done can help you decide which projects to take on first. Perhaps you know you need to fix your roof. Noticing that five neighbors have replaced their roofs recently might cause you to put that project at the top of your home-improvement list, Mr. Shuman says.

To avoid over-improving your home. “Make sure [improvements] are in line with what’s considered popular in the area,” Ms. Goodman says.

In a $150,000 home in the St. Louis area, for example, you may not get a good return on your investment for the installation of a granite countertop in the kitchen, she says. By seeing other homes, you’ll know what kind of finishes typical homes in the area have; that can help you make smart decisions when planning projects.

To get remodeling and decorating ideas. “For a lot of people, it’s fun to see homes, decorating styles, the layout of furniture,” Ms. Goodman says.

If you live in the same subdivision and your home has a similar design, it’ll be easy to steal some of the ideas — from how to arrange the furniture to how the living area would look if, say, a wall were removed to create an open floor plan.

To shop for a real-estate agent. If you want to sell your home soon, open houses are a good way to interview agents. Notice how attentive they are to prospective buyers walking through the property. And make sure they’re selling the home they’re standing in — only bringing up other listings when it’s clear buyers are definitely not interested in the home, Ms. Goodman says.

One of the reasons agents hold open houses is to meet prospective clients, so it’s a good opportunity to assess whether you’d like to work with that agent.

To gather comparables. If you’re selling your home, you may want to attend open houses to collect information about the competition in the area, says Joseph C. Magdziarz, president of the Appraisal Institute, a professional association that represents real-estate appraisers.

“Assessor’s records don’t always include all the improvements to a property,” he adds. “Appraisers rely on interviews with sellers and [real estate] brokers.” The only party who isn’t allowed to speak with an appraiser during the process is the lender or mortgage broker — whoever is involved in approving the financing, he says.

While it may feel awkward walking through a neighbor’s home, sellers and agents typically don’t take offense. “In today’s market, people understand,” says Mr. Magdziarz.

From their perspective, the more foot traffic they can get, the better, and they’re hoping you spread information about the home to family and friends who might be interested in buying it.

“You never know where that buyer is going to come from,” says Julie Ann Giachetti, a real-estate agent with Lang Realty in the Boca Raton area of Florida.

But be honest and tell the agent that you’re not a buyer, just an interested neighbor. “That allows us to gauge how much interest there is,” Ms. Goodman says. “Ten people, one buyer is very different than 10 buyers.”

Also, sign in with the agent, just as everyone else does — there’s a good chance your neighbor won’t see the sign-in sheet anyway, Ms. Goodman says.

Finally, in return for having a look around, give honest feedback about the home. “You can give us an honest opinion without jeopardizing your buying power,” Ms. Goodman says. This can help the seller address issues with the property.