Hayek called attention to the fact that not all orders involve a designer. There are also spontaneous orders. Matt Ridley (among others) elaborates. Some writers note that cities too can be thought of as spontaneous orders. Perhaps emergent order more accurately describes the ongoing evolution,
But both, designed and emergent orders, play big parts in our lives. Everything on my desk within reach involves intelligent design. But these are all the winners of design contests that we call "the market." In that sense, they are also emergent.
Americans still refer to city maps, but Germans (and many others) call it the plan of the city (Stadtplan). Is there such a thing. Many architects have dreamed of designing major parts of cities. They surely have designed large and notable urban structures and environs, including parks, airports, train stations, civic buildings and halls, cathedrals, public squares, theme parks, mega-malls, arcades, etc. So why not go bigger? How scaleable is design?
In between the various grand projects are very large numbers of much smaller projects (even the occasional stand-alone home or store). These also have designers but these designers must pass a market test. Can the resulting aggregation be called a plan? It is actually an emergent phenomenon. Failing to grasp all this, many simply call the vast developments (dark matter) beyond the monuments "sprawl."
This is the question implicit in Wade Graham's Dream Cities: Seven Urban Ideas That Shape the World. The author examines the ideas of various designers who dreamed of going big. The usual big-think suspects are mentioned: Burnham, Howard, Le Corbusier, Moses, Mumford, Soleri, Speer, and many more.
None can touch Corbu, "He prescribed three main 'DECISIONS' [caps in original] upon which the plan would be executed: '1. Requisitioning the land for the public good. 2. Take an inventory of our cities' populations: differentiation, classification, reassignment, transplantation, intervention, etc. 3. Establish a plan for producing permissible goods; to forbid stoic firmness of all useless products. To employ the forces liberated by this means in the rebuilding of the city and the whole country." Frustrated, Le Corbusier turned to the Soviet Union ..." but "... the Soviet authorities didn't bite either ..." (p. 91).
The following is much better."Productive cities are rarely planned and built from scratch. They evolve from the myriads of actions of their inhabitants. They are works in progress and they remain works in progress, responding as indeed they must, to new challenges and new opportunities." (Angel and Blei, 2015).