The article discusses the impact of the size of the shading caused by natural obstacles as the depth of the frame on the heat balance of the room, thus the selection and size of air conditioning equipment. Taking into account this phenomenon on the design stage, we are able to avoid wrong device selection, and thus reduce cost of whole installation. A thorough analysis of the affection of shading in passive construction through the use of shading elements, is an opportunity to reduce the flow of solar energy in the summer and thereby improve the energy consumption of the building.