I'll spare you the thesis and tell you that Danto defines an art object as anything with embodied meaning, that can be recognised and marvelled upon by the artworld. My association with Danto led me to define a work of architecture, as any building with embodied meaning, that can be recognised and marvelled upon by the architectural fraternity. Time since spent looking at designer bicycles, has brought about a slight evolution.
One class of buildings and bikes are valued for being exceptionally functional: the 6 Green Star energy rated building, or the Specialised pro team edition, for instance. An antithetical group of buildings and bikes, are valued for being designerly. They will invariably compromise utility, to draw attention to something visually intriguing about them. "Wow," we say of the Farnsworth house, "a building made from nothing but I-beams and glass." The fact that it is unliveable, only adds to our delight. "Wow," we say of the Ron Arad bike, "those wheels are made from steel petals." Anyone hung up on matters of traction, or noise, we look upon as a dull engineer who doesn't "get" anything.
This leads me to a definition of architecture, as opposed to mere building, not unlike Danto's definition of art, but more applicable to an art form like architecture, that will always be discussed in terms of a use. To be architecture, and not merely a building, utility will often be compromised, no matter how slightly, with the aim of foregrounding meaning, to people au fait with architectural thinking.