An essential aim of this study is to present principles of the legal interpretation of the term “building structure” for the needs of the imposition of a real estate tax. The analysis of both administrative courts’ judgments and the subject literature indicates lack of consistency in the scope of this term’s meaning. In my opinion, interpretative discrepancies are caused by incorrect legal interpretation of the legal definition. It should be noticed that numerous controversies connected with the legal interpretation of the term building structure are connected with considerable tax burden of this type of building objects. Taxpayers, for obvious reasons, are therefore “interested” in not finding the objects owned by them to be building structures in the meaning of the Tax Law, or possibly in finding only those objects’ specified parts to be building structures. It is easily apparent particularly in the case of objects of complex structures (e.g. cell phones towers, ski lifts, wind farms, facilities used in power engineering industry etc.). On the other hand, however, for many municipalities in Poland, income from building structures’ taxation creates municipal budgets. This way the practice of applying local tax law encounters numerous disputes between taxpayers and self-government tax authorities.