For a long time, the rural architecture of the upper valleys of the Alps have been perceived though a single glass: are the buildings made out of wood (the so-called chalet) or out of stone? This difference in the building materials was the main point of focalization for researchers since the early 20th century, starting with the work of Jakob Hunziker for whom it was an indication of the linguistical affiliation of the populations (German versus Romance), to which answered the Richard Weiss’s explanation phrased out in terms of ecological determinations. However, this debate overcomes the amazing unity of this architecture that offers a combination of three basic functions — living quarters, cowshed and heybarn — but declines them in many variations in regard to spatial arrangements in a matter that might be structurally analyzed. It is also tricking to observe the historical circumstances of the emergence of this rural architecture that seemed approximatively to occur between the end of the 16th century and the middle of the 20th century. An hypothesis emerges: this architecture is connected with the pastoral revolution, or in other words, with the implementation of a system mainly oriented to cattle-breeding for milk production. This orientation is aimed at a better rationality in exploiting natural resources, since it allows to maximize the potential resources in relation with the available manpower, thanks to the étagement of the landscape that loosens the seasonal imperatives of a grain harvest, so crucial in traditional plains agricultural systems. The relevance of this hypothesis has two main implications: what is the place left for cereals in these new systems? What kind of circulation it requires either for the humans (a good proportion of the population did not spend the winter in the upper valleys), either for the goods (the milky production must be exported), either for capital (building houses and acquiring cattle means investment) and either for ideas (the building technics are not archaic)? Such a reflection is also open to a discussion of the implications for the Alpine area of the two great principles of inheritance that prevail in Europe (undivided or egalitarian repartition) and of these respective roles of the state and of the religion in the process.