Mapping the interior of the building is the first step in order to obtain the description of that building. In this work, an autonomous robot is designed and built. The robot is able to navigate through an unknown environment, avoiding obstacles and simultaneously build a 3D map on its own. This autonomous feature is implemented using minimal and economically viable hardware such as Kinect v2 sensor and Arduino. Also, an open-source platform Robotic Operating System is used, on top of which the mapping and navigation algorithms are implemented. The 3D map built can be used with a lot of existing devices which involves localization. Post-processing procedures are used to obtain point clouds for building the 3D map. Emphasis is put on the efficient use of the available resources to generate the 3D maps of unknown indoor environment.