"The evaluation of the built environment, which is the subject of this lecture, underlines the need for creating on the basis of past experience. Indeed, all architectural creation originates consequences that should usually correspond to the starting intentions. Nevertheless, it may not succeed, and therefore it may have unpredictable secondary effects, both positive or negative. Very often this information is not recorded, and failures continue to happen. This is where relevance of evaluating and gathering all knowledge concerning relationships between man and built environment lays upon it must be a source of references, preventing in this way any arbitrary decision concerning the future users. The problem of evaluation in architecture is certanly not new; even before architecture became an organized profession, there existed a certain "spontaneous" evaluation. This aspect has been remarked by A.Rapoport and particularly by Ch. Alexander when he described the regulating mechanism of vernacular architecture as being the immediate identification with and reaction against a formal mistake or an unadequate element in the built environment. The architectural evaluation can fulfill a great amount of objectives; but, as a practising architect, the stress will be made on the evaluation of decisions on the process of design, on the design itself, and on the identification of unwanted consequences produced by the bull environment. During the lecture, the following points will be explained - Conceptual aspects of evaluation - Evaluating process - Limits of evaluation."