the action or process of putting up too many buildings in an area

during the housing bubble, prices soared despite overbuilding

the action or process of building on top of something else

the preservation of the medieval field pattern by direct overbuilding

put up too many buildings in (an area)

investors overbuilt the Atlantic and Mediterranean coasts

a lot of private schools have massively overbuilt

build on top of

the Romans overbuilt the existing Greek city