Most architects and construction engineers need to use modern energy analysis software for the purpose of improving their design. There is software within the BIM (Building Information Modeling) that are specific to energy which help to get the calculations of energy in an easy way. Building energy analysis studies in Iraq are few and limited and insufficient attention is given to this important stage in building design which is one of the necessary and important stages to obtain a good design In this paper, one of the existing buildings in one of the regions of Iraq was modelled by using BIM modelling software (Autodeck Revit). The energy analysis was then carried out by the (Autodesk Ecotect) software after exporting the previously modelled model. The results obtained are necessary to achieve the best design in terms of energy with the assumption of future changes in buildings that are similar in style and area conditions in order to optimize energy.