How can my value and taxes increase?

The value of property is determined by the Assessing Department, but the taxes are determined by the amount of tax revenue to be raised based on the Town budget.The real estate market determines the value of property and is indicated as "the most probable selling price" which tends to be the middle range of similar properties that have recently sold.  Therefore the assessed value could be higher or lower than what you paid for the property. The market value changes from year to year based on sales resulting from a number of influences such as supply and demand along with economic influences. Therefore, the Assessor does not create value. People create value by their transactions in the marketplace.

Also, if you were to make improvements to your existing property, for instance; add a garage, an additional room, renovate the interior of the house, the "full and fair cash value" would increase and, therefore the assessed value would also increase.