style of architecture vs architectural style

style of architecture and architectural style both are nouns.

Word	Noun	Adjective	Verb	Adverb
style of architecture	Yes	No	No	No
architectural style	Yes	No	No	No

As nouns, style of architecture and architectural style are synonyms defined as:

style of architecture and architectural style: architecture as a kind of art form

Other synonyms of style of architecture include type of architecture.

style of architecture (noun)	architectural style (noun)
architecture as a kind of art form	architecture as a kind of art form