Unmanned Aerial Systems (UASs) have been proven a useful utility for mapping or site scanning purposes. Practical applications emerge in the form of inspecting structures that are hard to reach, deterioration analysis, construction monitoring or quantifying material in landfills. From a technological perspective many of these applications rely on the same established methods, namely GPS-driven navigation or even manual flight. While ongoing research is focused on developing reliable means of obstacle avoidance, sophisticated mission planning solutions can greatly increase the practicality of UAS for inspection purposes. We propose an inspection planning concept for highly automated inspections in BIM projects. The application, developed in the course of this research, interacts with the firmware and the simulation capabilities of the Dronekit framework, which makes for a highly integrated and sustainable UAS. The main contribution is the 3D simulation of planned flight missions with Software-In-The-Loop (SITL) technology. The inclusion of actual flight dynamics allows the operator to perceive an authentic representation of the UAS's behaviour before take-off. Furthermore, the web-based planning application renders preview images in the virtual scene which provide a realistic impression of the results to be expected. The application automatically generates the different waypoints for obtaining photographs of a point of interest.