At nearly 44 minutes into the episode, Jeanie looks out of her window when Al leaves for Atlanta. The apartment was built above the ambulance bay set at Warner Bros. Studios, which is quite unusual since the studios normally build sets on the ground level of sound stages only.In one of the audio commentaries in the season 3 DVD box, they mentioned that they built an apartment set above the ambulance bay and redressed it for various purposes.If you know, it's pretty obvious though: When Jeanie looks out of the window (43:56), we see the fake El tracks through the window. The curb across is New York Street on the backlot of WB Studios. From the outside, you see a horizontal balustrade (or something like that) in the window. This matches the window on the second floor of the hospital's exteriors.