Using 3D is becoming more and more common for professionals as well as users, e.g. Google Earth and its 3D view. Implementing a mobile application that takes advantage of 3D and Augmented Reality (AR) will be very useful for planning new constructions in both urban and non-urban areas allowing to visualize how the construction will be in the future and how it will interact with its surrounding environment. A good example is modifying an urban area and allowing the inhabitants of that area to preview the project for avoiding unnecessary conflicts related to the project. In non-urban areas it helps decision-making by visualizing the project on site. Previewing a future construction requires having a digital 3D model. Together with the 3D format called COLLADA, the CGI and gaming technology called OpenGL ES 2.0 is used. Combining them with the views’ properties, the camera, the mobile device’s sensors and the positioning technologies allows displaying 3D in an AR environment. The results show the advantages of combining technologies in a smartphone and the challenges that the low accuracy in positioning entails. Thus, ideas for improving the positioning accuracy are discussed as well.