Days of Wine and Roses - Kirsten's Place
At dinner on their first date Joe introduces Kirsten to the seductive charms of a Brandy Alexander. She hasn't drunk alcohol before but tells him he was right - it made her feel good. She doesn't know it yet but she just stepped on the slippery slope.
Then ... Their cab drops them off outside her place.
Then ... When we get to see inside her apartment later in the movie the view from the window is the clue to its location ...
... and Now, the same view today.
... in 1970 ... Based on the view, 298 Union Street on the corner of Montgomery was the virtual location of Kirsten's (and Midge's) place. This vintage photo shows how it looked when the movie was filmed. But to get that unimpeded view west the photo for the window view must have been taken from this or a nearby rooftop.
Then ... Another window view, looking east, was seen from Kirsten's place. This looks down to piers on the Embarcadero but it's a view that couldn't be seen from the 296 Union location, further confirming the use of a studio set.
... and Now, the pier bulkhead seen above appears to be Pier 23; this recent photo of it was taken from Montgomery Street at Filbert, a block from 296 Union.