Current situation concerning the environment and the human kind perspectives requires unconventional approach for every activity of civilisation including building industry. The need for energy and raw materials savings impose special attention which has to be paid in assessment of cost and energy demand for the whole life of building structure. It seems that steel, and especially weathering steel, is one of the materials which could fulfil at least part of the criterions regarded for structural material. The paper aim is to present the advantages and discuss disadvantages of that structural material in terms of circular and environmental friendly economy in constructing engineering structures. The study will be filled with some case studies which allow for quick verification of the problematic part of the paper.