For years, the mantra of American homeownership was to count on home appreciation. Every year like clockwork the value went up and houses were a  growing source of wealth.

Now, more than three years after the housing market imploded, the tune is different. It may make sense for you to prove that your home’s value has dropped so you can file for reduced property taxes.

This is the time of the year when local assessors send out notices of your home’s assessed value. Note, however, that this is not your real market value. It’s a base value that’s used to calculate your property taxes. If you want to reduce your real estate taxes, start with paring your assessed value.

You have a reasonably good chance of winning a challenge to your assessed valuation. It’s estimated that some 60 percent of residential properties are over-assessed, although only a handful of home owners appeal, according to the National Taxpayers Union.

As someone who’s volunteered with a local non-profit in Northeastern Illinois on property tax issues, I know it’s worth fighting assessments every year. Sometimes I win, sometimes I lose. If you feel that your assessment is too high, there are many ways to challenge it, but it takes some homework and diligence.