This is a poor way to estimate value. It gives the average joe many times the wrong information that may hurt both the seller and buyer of real estate. As a builder/realtor,(1) first I look at the land values in the subject area, This gives me a sense of how two very similar homes in different parts of the same town can have two different values. Land use can throw the numbers off aswell. Now you have historic home values, single level verses multi level home values, multiple bathrooms, inlaw suites, new, rehabbed, good and poor conidtions values. And the list goes on. When choosing your realtor make sure he or she knows the difference. Many look at the assessment value and base opinions solely on that towns assessment. Buyer and seller beware!