During early building design stages, decisions are made regarding building's form, orientation, distribution, and size of glazing. Although these features are crucial for building energy performance, designers rarely base their decisions on elaborate energy simulations. The paper presents a study of the interconnectedness of building form, orientation and window area in regard to energy consumption for heating and cooling of a generic building in Central European climate. The study showed that for the considered climate, an elongated building form is more suitable than the compact one, because it allows larger window areas and thus more efficient solar energy harvesting. Even though this may be advantageous for the heating period, it represents a potential problem during the cooling season. Therefore, appropriate shading must be applied and thus the optimum solution is achieved in regard to the building's cumulative yearly energy consumption.