Raumplan

"My architecture is not conceived in plans, but in spaces (cubes). I do not design floor plans, facades, sections. I design spaces. For me, there is no ground floor, first floor etc.... For me, there are only contiguous, continual spaces, rooms, anterooms, terraces etc. Storeys merge and spaces relate to each other. Every space requires a different height: the dining room is surely higher than the pantry, thus the ceilings are set at different levels. To join these spaces in such a way that the rise and fall are not only unobservable but also practical, in this I see what is for others the great secret, although it is for me a great matter of course. Coming back to your question, it is just this spatial interaction and spatial austerity that thus far I have best been able to realise in Dr Müller's house"

Adolf Loos, Shorthand record of a conversation in Plzeň (Pilsen), 1930

The composition of the inner, primarily residential spaces in the family houses of Adolf Loos is based on entirely unique architectural thought, on the principle of the spatial structure of the plan, the so-called "Raumplan". "Raumplan" is embodied amongst other things by Loos' understanding of economy and functionality, and Loos applied it in his designs for social housing. "Raumplan" rests on the stepped heights of the individual rooms according to their function and symbolic importance. The organisation and division of interior space delineated by "Raumplan" can also be traced in the outer walls, on the facades. A vertical plane of undecorated outer walls runs around the lower level of the plan, and only on the upper floors does it divide into several mutually offset levels, which form for example the plinth of the underground rooms or a protruding balcony. As a result the facade appears to be a composition of offset and recessed planes.

http://www.mullerovavila.cz/english/raum-e.html