Beside industrial scale large wind turbines there is an increasing demand for lower capacity, household scale wind turbines recently. An important advantage of such small wind turbines is that they can be established in urban locations and they can produce electricity in online and offline mode either. While the height of the towers of industrial scale wind turbines is over 50 meters (or even over 100 meters in the case of offshore wind farms) usually, household scale wind turbines are mounted on masts not higher than 30 meters. The main reason for this is higher the buildup density and regulations in the urbanized areas. Important conditions of the establishment of small wind turbines are local wind speeds and wind directions influenced strongly by the highly complex and at least partly artificial relief of a given location in urban and suburban environments. Physical characteristics of the surface are described by the surface roughness parameter. Calculation of the roughness parameter requires a detailed database on the elements of the relief of the study area. It consists of the position, horizontal and vertical area and height of each relief elements. Values of surface roughness and changes of local wind conditions can be calculated on the base of the before mentioned data by the 4 main and 4 sub wind directions. Digital surface model (DSM) of the study area has been constructed using UAV (Unmanned aerial vehicle) images in the frame of examinations presented here. This method makes much faster, simpler and cost effective the production of datasets necessary for the calculation of surface roughness. Four study areas located in characteristic morphological units of the city of Debrecen were chosen for the study. A digital surface model have been built for each areas using UAV images. Accuracy of the models has been verified by 3D laser scanning (LiDAR).