Building Information Modeling (BIM) prepares quantity take-off of construction items, helps the management of the design and construction process and prepares 3D visualization of the construction phases. BIM offers more control over the construction tasks and improves the efficiency. Construction professionals are aware of the benefits of BIM however, the utilization of BIM is still not common yet because of the BIM software cost and training requirement of the staff. In this study, open-source BIM software is developed by Python programming language. The software is capable of preparation of 2-dimensional drawings, 3D visualization as well as execution of quantity take-off computations of formwork and concrete. The codes are developed in Python language by using SQlite library and Ursina engine. A graphical user interface is formed by Python language for the execution of 2 Dimensional drawings and entries of the coordinates of the structural elements as well as attribute data. 3D coordinates of the structural elements are computed by using the joint coordinates of the structural elements. 3D visualizations of the structural elements are performed by the Ursina engine. The connections and intersections of the joints and structural elements are stored in a database that is formed by SQlite. The voids are successfully computed and formwork and concrete quantities are computed. The open-source BIM software would have low investment and operational costs for the construction firms and would increase BIM usage. The utilization of the software would decrease the manmade errors during the quantity take-off preparation step.