Synthetic vs Authentic

I am currently sitting in a retrofitted warehouse recently converted into a bar. The bones of the space are authentic and the newly installed bar is what I would classify as synthetic (added paint, synthetic material selections for longevity , ect.) I am using the term synthetic in this case as an object without history. It does beg the question, at what point does the synthetic become the authentic? I carry this question forward to experiences as well? Looking around I realize the wall mounted directional oscillating fan has roughly the same amount of accumulated dust as the roof structure holding up the standing seam metal roof. The two have morphed into a new class, one simply classified as retrofit.