Architectural morphology is an important factor for the prediction of soundscapes and noise propagation in urban areas. As in room acoustics, the sound field in a street is characterized by the building façades irregularities, in such a way that two similar streets (in size) can produce two different sound fields for two different building façades. However, most of the existing softwares and models take only the specular reflection into account implying a significant uncertainty in the sound prediction. The main purpose of this paper is, first, to investigate how the sound field and urban soundscape perception are influenced by building façades, and secondly, to characterize several urban façade by typical reflection laws. Then, a coupling morphological and acoustical database will be built up and introduced in an urban acoustics simulation software, in order to be used by town planners and architects in urban projects. This paper is a part of the national land transport research and innovation program (PREDIT) and is supported by the French ministry for ecology and sustainable development.