Aha. Here's where it becomes tricky. I'm trying to make real-world sense of a fictional building layout which didn't need to make any sense in its fictional depiction. So it is full of impossibilities and contradictions. I'm trying to faithfully retain (most of) the features that we can readily observe in the video evidence of the TV show, while filling in the blanks and reconciling the contradictions as well as possible.
But then we come to the freight elevator.

The size I have on the previously posted floor plans is far, far too small. Batgirl in heels is between 5'4" and 5'6" tall, approximately. Properly proportioned for that height, her Yamaha Batgirlcycle must be at least 5'6" tall (perhaps taller), which makes it about eight feet long. The blue blob I have added to the attached image shows the outline of the Batgirlcycle, to depict its scale. The elevator needs to be much, much larger to accommodate the size of the motorcycle.
Which causes problems. The freight elevator is at the corner of two walls with known angles, both of which have exterior windows on them (marked as A and B on the attached). I can't move the walls much at all, yet the elevator needs to be larger. The only real option seems to be making it jut out of the side of the building. In which case it is an obvious structural trait of the building, and unlikely to be a secret. Meanwhile I have already fudged the angles and positions of the walls in the Secret Room, to try to allow the freight elevator to fit in at all. I don't have much wiggle room.
This is as impossible as the area I've designated as the Impossible Space on the floor Plan, which is a section of the plan where we have contradictory evidence about what lies in that space. Per episode 95, that is an exterior wall, with a window through which Batgirl enters on her return trip from apartment 8B. However, if that section is an external wall, then the outer contour of the building is absolutely surreal and unlikely, with the angles contradicting what we see in the bordering living room. This problem is smaller than the freight elevator problem, because the elevator is prominent in the storytelling while that window appears only in two seconds of one episode, and can perhaps be more easily glossed over.
On the attached image, I've shown known lines of sight which reveal relationships of elements in the bedroom and living room. We know how a lot of this has to fit together. But, this being a TV show, they didn't worry about whether any of it made sense. Barbara Gordon lives in an impossible, contradictory space.

And now I'm having trouble figuring out how to resolve some of the contradictions. Hmm.