Imagine a modern factory. In all probability you will envisage an oblong building, with a flat roof supported on steel girders, standing unconnected to its surroundings in a field of concrete. You won't expect the windows to be placed in any particular position, nor will you imagine anything significant by way of a door. The typical modern office block is taller, squarer, finished off with a grey-green veneer of glass. It is striated like a chest of drawers, with the divisions between the storeys marked by metallic lines. It rises from the middle of streets and houses, but, as a rule, belongs to no particular street, and makes concessions to no discernible plan. Its angles dig into the surrounding town, and all the way up to its flattened summit it spreads itself in long horizontal wedges of glass. If asked to envisage a modern apartment building, you will probably imagine something more like the factory in its setting, more like the office block in appearance. It will be greyer than any office, drabber, with smaller windows interspersed by slabs of discoloured rendering. But, the horizontal divisions will be just as clearly visible, partly because each floor is an exact replica of the one beneath it, differing, if at all, only in the colours of the drapery. And, as with the factory, the whole block will be surrounded by a clearing, this time of muddy grass. In none of the three cases are you likely to expect any clear relation ...