After constructing a building in-game you are only allowed to place it near your existing Structures.
specifies the maximum number of cells away from one of your existing buildings (that does not have set) that you may place the new building. An adjacency value of zero means the new building must be placed in contact with an existing building - there must be no gap. An adjacency value of 1 means there can be at most a 1 cell gap between an existing building and the new building.
A building withset can be placed both 1 cell North-East and 1 cell North-West of an existing building at the same time (i.e. diagonally).