Upzoning and downzoning are fairly different: upzoning often immediately precedes building larger buildings. Downzoning puts an upper bound on growth, but neve

Upzoning and downzoning are fairly different: upzoning often immediately precedes building larger buildings. Downzoning puts an upper bound on growth, but never results in a building being demolished (except in cases of a derelict building, where downzoning makes it impossible to replace – though even then it's usually possible to create replace a building with an equivalent building regardless of zoning in the case of something like a fire).