rebuild vs building

rebuild is not a noun while building is a noun.

Word	Noun	Adjective	Verb	Adverb
rebuild	No	No	Yes	No
building	Yes	No	No	No

rebuild (noun)	building (noun)
	the act of constructing something
	the commercial activity involved in repairing old structures or constructing new ones
	a structure that has a roof and walls and stands more or less permanently in one place
	the occupants of a building

rebuild (verb)	building (verb)
build again