church building vs kirk

church building and kirk both are nouns.

Word	Noun	Adjective	Verb	Adverb
church building	Yes	No	No	No
kirk	Yes	No	No	No

As nouns, kirk is a hyponym of church building; that is, kirk is a word with a more specific, narrower meaning than church building:

Other hyponyms of church building include abbey, basilica, cathedral, cathedral, duomo.

church building (noun)	kirk (noun)
a place for public (especially Christian) worship	a Scottish church