How much would my taxes be on a new building?

Depends on the type of building, its use, its size, your location

Example: A property owner in Washington Township states they are going to erect a pole building for around $20,000 to be used for farm machinery. Formula: $20,000 x 25% (ag improvement assessed rate) = $5000 (assessed value) $5000 x .111817 (mill levy in Washington Township) = $559.085 taxes