Venustatis firmly stands as the most important of the Triad, as to me it is the most distinguishing difference between Building and Architecture. The addition of beauty, of something that is difficult to define, helps to establish that Architecture is driven by ideas and conversation, separating it from merely building a structure out of necessity, there is thought or emotion that drives the design. Further, I would rank Firmitatis over Utilitatis. I think that the ability to have stability and endurance through time is more important than it serving a desired purpose or function. We easily discuss the structures from Ancient Greece because they endured despite losing their original purpose.