Defining the volumes you see from the urban space can sometimes mean drawing elements that have no usable floor area, as walls. A part of the most interesting spaces in historic Paris, mainly in the areas with “hotels particuliers” is defined through walls hiding from the view courtyards or gardens much bigger than the public space. The same applies to Toledo or Segovia. Muslims cities have long used this principle, often with less elaborate walls. The transition from public to private space is enriched; drawing just the big built up volumes is somehow cheating.