Architects are now capable to construct diverse architectural compositions with various formal attributes. Although theorists have defined diverse sets of composition attributes, no former list covers the features of our newly built buildings. This study, for the first time, introduces a systematic method to define all the visual attributes in the composition of a building. Arising from the definition of composition, the proposed method, after defining the composition layers and families, prepares a composition graph; then, by introducing three roots of the attributes, it creates a list of the visual attributes. To give a better insight, the method applied to four buildings and their visual attributes are extracted accordingly. The employment of the procedure on a set of building images sharing a criterion can reflect the most in-common formal attributes among them. Therefore, a list of building attributes are also prepared by applying the method on 200 randomly selected building images. The proposed method is adjustable to our needs and also applicable to various art forms which the term composition covers. Consequently, the introduced method has the potential to be an assistive tool in many formal explorations studies.