June 10 (Bloomberg) -- As home values drop, your property taxes should do the same, right?

Unlike sales and other excise taxes, you have a small amount of control over your property taxes. Yet you will only see results if you challenge the assessed value of your home, something that only a few owners do.

Why is it that so few taxpayers try to reduce their property taxes? While as many as 60 percent of all U.S. homes may be overassessed, according to the National Taxpayers Union, most don’t know how the process works or that they even have the right to appeal.

You are likely to have more success this year because there is a large disparity between assessed values from the boom years and depressed current market values in most areas.

Most likely your home’s assessment is out of date since it is based on an average of local values that may go back as long as three years. Since the height of the boom market, prices have declined by 20 percent to 50 percent.

Appealing your assessment is something anyone can do, yet it is important to do some preparation work to ensure success. This is something I do almost every year. I have been able to lower or freeze my home’s assessed value several times.

How to Appeal

Having battled with my township assessor for years and formed a local nonprofit group to promote assessment transparency, I can confirm there’s often little accountability in how they value your property. They make mistakes, and assessments may be wildly inconsistent in your community.

It’s time to do some homework. Your first bit of legwork involves checking your home’s legal description. Does it match precisely your house and lot characteristics? There may be errors in their records on the number of finished rooms, lot size and interior square footage in your home.

Say your assessor records your home as having five bedrooms and you have only four. Produce a set of blueprints or have them inspect the home. The discrepancy may instantly lower your property assessment.

The second step is to determine whether you are fairly assessed. You will need to work out whether similar houses sold at lower prices than your home’s current market value. Are there any local features that will reduce your property’s value? Railroads, highways, landfills, easements and re-zonings (to commercial) count.

You can present these details to your assessor before you file a formal appeal, but don’t expect him to give you a reduction. Most states have bodies that deal specifically with real-estate tax appeals at higher levels.

Higher Appeals

When appealing, you will have a solid case if your “evidence” of at least three to five comparable homes -- those closely matching yours in the number of rooms, square footage, lot size and type -- show lower relative market values.

If you don’t feel comfortable researching and filing your own appeal, you can hire an attorney. They are usually compensated by taking a percentage of your tax savings.

Appeal boards also tend to respect the opinion of a certified real-estate appraiser more than yours. Spend a few hundred dollars to present a recent certified appraisal and your chances of winning a reduction typically rise.

Be professional and precisely document your case. Appeals boards are swamped right now. Ocean County, New Jersey, for example, is facing more than 14,000 appeals this year, a record number in the state with the highest property taxes. In some counties, assessment challenges have tripled.

Stay Focused

Typically you will have just a few minutes to make your appeal. Keep in mind it isn’t a court of law and you have to meet strict filing deadlines.

Don’t expect an immediate reduction in property taxes, either. Taxing bodies still have the power to raise levies or float referendums if they need funds. Your taxes may rise -- even in this market.

If the deadline for appeal has passed this year, start building your case for next year as market values may decline further in your area.

Definitely mount a challenge if you are in the highest property-tax states, such as Connecticut, Nebraska, Pennsylvania, Ohio, New York and Massachusetts, according to the National Taxpayers Union.

If you do about an hour’s worth of careful research, you may be rewarded by a lower tax bill. It is one of the few benefits of this housing recession, so take advantage of it while the market is still reeling.

(John F. Wasik, author of “The Cul-de-Sac Syndrome,” is a Bloomberg News columnist. The opinions expressed are his own.)

To contact the writer of this column: John F. Wasik in Chicago at jwasik@bloomberg.net

Last Updated: June 10, 2009 00:00 EDT