building vs rebuild

building is a noun but rebuild is not a noun.

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

building (noun)	rebuild (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

building (verb)	rebuild (verb)
	build again