It's looking good - I like the way you have tried to remain faithful to the building footprint.

If I may offer a few suggestions, I would be tempted to have the roofed upper floor section be really high so it can have massive windows to allow in light. I think your outer building wall should be thicker too as currently it is the same width as the internal walls. And some large pilllars in the central atrium to support the upper sections would make sense structurally and would be interesting features.