I had a gazebo put on my deck and my property taxes increased more than $700. When I asked why, the answer was because it was considered a part of the house! I asked if my taxes would have increased it I had the gazebo put in the yard and the answer was yes. $4000. gazebo = $700+/yr more in property taxes.
My taxes are well over $3000. a year and my house was built in 1960!! Small four bedroom, lot and a half, corner lot, older neighborhood!