Space needed for L-shaped staircase with 2 landings
My condo has an L-shaped staircase that I've been thinking of replacing with a new staircase to save space. The present staircase is 45" wide on top (33" square landing corresponding to 33" width of steps + 2 steps), 33" wide on bottom (width of steps) and 12' feet long. Floor to floor is 9'2" high. I was thinking the new staircase would follow the layout at top, but halfway down the straight run of staircase, take a 180 degree turn. In other words: 2 steps at top - landing - 90 degree turn left - 6 steps - 180 degree turn left - 6 steps. I asked an architect who has seen my place and understands the layout (but does not know exact measurements) whether he thought a U-shaped staircase would work (admittedly, I didn't tell him exactly what I had in mind as described above to see if he would have a different idea) and he said that it would require 12' x 6.5' of space for the 9'2" height. I don't understand this at all because it is almost double the space taken by my current staircase. I figured, roughly, that since what I want to do is turn the long part of the staircase halfway through at 180 degrees, the staircase would be about half as long but twice as wide, so approximately 7' x 6'. Could anyone shed any light on this?
Related question: because of an obstructing column/wall, I have only about 65" long x 53" wide of space in which to put an alternative staircase, assuming we keep the same layout in the rest of the apartment. This space can be marginally bigger if some changes to layout are made. Notwithstanding my realizing that there are probably lots of variables I'm not taking into consideration, I think it is conceivable to put in the staircase I described above into this space while meeting code, assuming the staircase curves in place of a landing..?? Could anyone tell me if I'm completely crazy to think this or not? I have looked into the free staircase calculators but they don't seem to work for the shape staircase I am looking for.
I know this is not a strictly DIY question (I'm doing other DIY, but staying away from the stairs, which are well outside of my limited skills), but I'd appreciate some advice all the same. Thank you!