In order to locally produce electricity in urban areas, it is important to properly assess the potential of the Buildings Integrated PhotoVoltaic (BIPV) technologies. Therefore, the evaluation of the incident solar radiative flux in dense urban areas, taking into account multiple reflections over all urban elements, is a current subject of interest. Although different models exist to evaluate the intensity of the power density on each zone of each part of an urban scene, the reflective properties of the different urban materials are generally simplified, and they are commonly supposed to reflect uniformly wavelength through the space. Henceforth, this brings up questions about the relevance of these assumptions and their influence in the numerical evaluation of the PhotoVoltaic (PV) potential. Thus, this paper reviews the different alternatives to proceed with a preliminary evaluation of the solar potential in dense urban areas, with the aim of evaluating the influence of the material reflection properties on the power density incident on a fac¸ade. Two models are discussed: one based on the radiosity method and the other based on the raytracing method. The construction of both methods is detailed and results for both models under similar hypothesis are compared. Moreover, the influence of different reflection properties is also studied.