"A demonstration of the systems and conventions on which the dwellers elaborate their aesthetics judgements about detached houses. One of the origins of today's crisis in modern architecture can be explained through the divorse between form and the idea that dwellers have of architecture. Dwellers base their aesthetic judgements on a system of basic agreements that no builder can disregard without condemning himself to the most absolute insignificance We have gathered a set of photographs of industrialized houses taken from a catalogue and then asked the users to talk about then. We have registered two different types of approaches -The one based on a predicative system by means of which the dweller describes the qualities that he perceives in such or such a house, reconstructing the data that he gets from the set of images. Concerning the aesthetics of the house, main object of our research, it became evident that the inhabitant established a connection between use and quality, a connection which constitutes the specificity of his words, and which gives him such a strong foundation that not even architects can discuss it. - The one based on a system which enounciates the categories of aesthetic judgement; the dweller then talks about the Aesthetic, relating his own taste to that one of the creator. For him it is a matter of judging "the effect". Among these categories, the category "nice" -which really is the feeling of "nice"- is basic for the aesthetics of the house. These two series of approaches allow us to state that the dweller also establishes a real aesthetic code, which enables us to talk about his vital competence."