Yes , a taxpayer have full right to disagree with the assessed value . He/she can appeal to the assessor's for the property review.

 True Tax Value is extracted from the sum of the land value and the depreciated value of improvements .Land value is the market value of the land of that area and improvements includes   houses, barns, garages, swimming pools, decks, patios, utility sheds, tennis courts, gazebos, carports, etc.