PG did start a founders first vc firm. It's called yc, and they have a nondescript office in mountain view and tell you yes or no after a 10 minute interview.
The building is pretty plain in an off-the-beaten-path location that you could easily miss. I think "nondescript" is a pretty good adjective for it.
I was thinking of the interior. I guess you're right considering the outside of the building. However, that's like almost every building in the valley. Sand Hill Road isn't exactly an architectural tourist destination, either.
The interior too. It's pretty non-descriptive (and orange) compared to most company / vc offices.