An interesting note: Barris is wearing the same clothes as in the posed Nineteenth Hole shot. Now, it's possible they were taken on the same day, but it could be possible that Barris wore his Kustom Kars jacket and jeans combo whenever he visited a set
In Season 3, Hasselhoff wears the black shirt in: Knight of the Drones (with gray pants), The Ice Bandits (with gray pants), Knights of the Fast Lane (with gray pants), K.I.T.T. Vs. K.A.R.R. (with black pants), The Rotten Apples (with gray pants), Knight in Disgrace (black pants), Dead of Knight (white jeans), Knight and Knerd (black pants), and Knight Strike (black pants).
As far as the building, it all depends if it was meant to feature in the show. If not, it doesn't help as an identifier. A good example of this came in the thread about the camera crew in Soul Survivor. Behind the camera crew you can see buildings, but in the episode those scenes took place in wilderness. The magic of moviemaking!