The role of building form in energy consumption: The case of a prismatic building in Athens

► We model a prismatic building and its orthogonal version for energy simulation. ► We examine annual differences in energy consumption according to building form. ► Prismatic formed building has lower solar gains compared to orthogonal version. ► Prismatic formed building consumes less energy than orthogonal version in Greece. This paper examines the behaviour in energy consumption of buildings that have polygonal and prismatic envelopes and are located in Mediterranean climates. More specifically, it aims at studying the differences in energy consumption of these kinds of buildings compared to orthogonal building envelopes. For this purpose a contemporary building was chosen and modelled in two different versions, one being the original prismatic form and the other a model of the same building with right angles, however retaining all area and volume data of the original prismatic building. Calculations reveal that the prismatic formed building has lower solar gains compared to its orthogonal counterpart and consumes less energy in an annual cycle. The results show a mean annual energy consumption difference of 7.88% in favour of the prismatic building envelope. Also, depending on the orientation, the difference in annual energy needs has a range between 2.51% and 16.01%.