The main purpose of this article is to present the problem of establishing real estate tax base. In Polish legislation in the case of buildings it is usable area understood as an area measured according to internal length of walls on all floors that constitutes the real estate tax base. The area of staircases and lifts are not included in this usable area. However, as far as constructions are concerned, this is the value, which functions as amortization base calculated in the case of income taxes, or the market value that constitute real estate tax base.
