This is a sign of appreciation, which is not a bad thing. Your property taxes should not increase more than $300.00 for the year, or $25.00 per month. You can protest the evaluation, but you will need valid supporting comparable sales. I would be happy to look at your property and the available sales data and give your an educated opinion. Keep in mind that you will need to report the improvements you have made, and their estimated value during your protest. Subtracting the new improvements, you stand at an $8,000.00 increase in value which equates to an approximate $240.00 increase in annual taxes. PErsonally, I would strike it up as a win that your improvement at $2,000 netted you an increase in value of $10,000.00.