outside door vs building

outside door and building both are nouns.

Word	Noun	Adjective	Verb	Adverb
outside door	Yes	No	No	No
building	Yes	No	No	No

outside door (noun)	building (noun)
a doorway that allows entrance to or exit from a building	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