Flickr / Mark Moz.

After nearly 20 years as a property tax assessor in a small town in Massachusetts, I have fielded a lot of questions and heard many complaints concerning property taxes. As you might expect, the two most common gripes are, "I'm paying too much in property tax" and "My house is overvalued".

Of course, there is nothing that tax assessors can do about the first issue – generally, town government establishes the tax rate via the municipal budget – but, sometimes, there can be a remedy to the second problem.

If you feel that you are paying more than your fair share in taxes because your property's valuation is incorrect, there are steps that you can take to rectify the matter. While I can only speak about how property valuation works in Massachusetts, most states now use 100% fair market value for valuation purposes, meaning that sales of comparable homes are used to assess properties that have not changed hands. However, check with your own assessing department just to be sure.

Obtain a copy of your property record card from your assessors' office. Getting a hard copy is important, since online records are often incomplete. Even if you have to pay copying costs, they will be minimal – and well worth it.

Check square footage
This is an essential first step, because this field record should mirror the type and current state of your property. If it doesn't, and the error is in your favor, chances are good that you will be able to win your case.

One of the most common mistakes people see on their card is an error in measurement. More than anything else, homeowners are taxed on the square footage of their buildings, so this point is crucial. The actual house is the most important metric, since homes are more valuable than other buildings, such as garages.

Measure all of your buildings at the foundation level, and compare your results with the information on your property card. Sometimes, even small mistakes can add up to large savings.

Number of rooms: running water counts
Though property owners often think that the number of bedrooms makes a difference in their assessment, this is often not the case. There are two types of rooms that generally do matter, though: bathrooms, and kitchens.

Flickr / Jeremy Levine Design.

Often, cities and towns will value bathrooms according to how many fixtures they contain: full, three-quarters, or half. Each will have a different assessment, so double check this item.

Kitchens are usually straightforward, except in the case of an apartment, such as an in-law unit. Also, think creatively when scrutinizing the card. Make sure, for example, that your finished basement's wet bar hasn't been assessed as a kitchen!

Type and condition of house
The style of your home can make a large difference in your square-foot assessment. More popular types of houses, such as colonials, are often valued more highly than one-story ranches – both by home buyers, and assessors. If you think your home should be categorized differently, speak with your assessor. Sometimes changing a home's classification from, say, cape style to contemporary, can yield great savings. You will need to prove that there is a valid reason for doing so, however.

Your home's condition can also affect the dollar-per-square-foot assessment. This is somewhat of a judgment call, so you may be able to knock your home's condition or grade down a notch or two, if you are persuasive. Sometimes, the difference between "excellent" and "very good" is minimal in perception, but may have a sizable effect on your property's valuation.

Make sure you have all your arguments ready, and any documentation you may need, before you set up an appointment with your assessor. If there are glaring errors on your field card, the assessor may fix it without a formal procedure. Otherwise, you might have to file an abatement during the proper time frame, information on which is commonly sent along with your tax bill. If this is not the case, simply ask.

Keep in mind that your assessing department will need to inspect your home to ascertain whether or not there is a problem – which means that your valuation could conceivably rise if there have been improvements to the home of which the assessors were unaware.

If you do your research and present your case with substantial documentation, chances are you will prevail. It will take a bit of legwork, but the money you can save over the long term will very likely be worth the effort.