Thanks for reply, it’s not an actual “roof” it’s like a balcony, structure and transport wouldn’t be an issue there.
As far as the coop goes, I have enough space to go slightly larger. Do you have any idea of any plans available?
If we can sort out some terminology: it helps if you call the mostly wooden structure in the picture the coop. The screened part is the run. They sleep and lay eggs in the coop; they play and hang out in the run.
The smallest square footage recommended for the coop is 4 sq ft/ chicken. From the drawing, you MAY have 12 sq ft, which fits that math, but it's not going to be enough in your situation, especially when it's going to be hard to get away from one another when cabin fever hits.
Since you aren't going to be able to yard range (roof range?) on a rooftop, they are going to need a huge amount of run space. The typical amount recommended is 10 sq ft per bird, but again, in such a confined space with absolutely no option to be let out, 15 or 20 sq ft/chicken is more like it. Presumably, you're going to want some human space up there where you can enjoy the skyline in the evening, and trust me, you won't want to be sitting in chicken poop in the run. If you have 10x20 as mentioned above, will 40 sq ft (5x8) be a big enough spot for a few chairs and small table?
You may want to rethink this. At a minimum, consider 3 bantams instead of standard-sized chickens. Eggs will be smaller, but they're just as tasty, and the sizes might be more manageable.