Homeowners obviously benefit by a larger equity when their home increases in value due to appreciation. A not-so-obvious effect that will also more than likely take place is that their property taxes will increase. In most cases, a property's assessed value is generally tied to market value to calculate the property taxes based on the tax rate for that year.
Similarly, a homeowner can affect the value of their home by making capital improvements. Some small items may never be recognized by the taxing authority but items that require a permit, certainly are brought to their attention. Items such as a fence, roof, remodeling, windows, new rooms or swimming pools can easily increase the assessed value of a property.
Most states have an established time frame in which to challenge the current tax assessment for that year. The process is relatively simple and doesn't require professional representation. It generally involves showing that there is an error which has overstated the value or that current comparable sales indicate a lower value.
If you'd like more information or need the comparable sales data, please let me know. I'd would be happy to help you investigate the possibility of lowering your property taxes.