The 20th century attests to the failure of unlimited and juvenile confidence in the possibilities of mechanization, confidence of the kind that did not justify the abandonment of the traditional filters of comfort. Due sometimes to ignorance and almost always to stylistic impositions, an elaborate current of knowledge and artifacts was destroyed that made it possible to adapt architectural spaces to changing and personalized objectives of comfort.

The limitations of mechanical applications to architecture were such that up to the 1940s, the matter of comfort was almost exclusively entrusted to passive systems, with some exceptions that incorporated combustion. Hence the marvelous development of the bourgeois window, equipped with a range of filters that allowed highly sophisticated nuances of comfort. The most diverse forms of blinds, shutters, and curtains made it possible to adjust conditions of light, privacy, and shade to the activity of the moment...