I choose the Steel-frame System with a beam max of 50' and beam size of W12x26. I think steel is a nice offset to all of the wood present in the existing architecture of the building. I decided to make the grid around the current walls/atrium/stairs to ensure that there was nothing running through what should be an open space. I believe I kept the hallways clear. There are a couple of things I need to make sure I check on my model before I begin the structural framing process. 1. That I am framing the correct level (reverse of how AD thinks of floors), 2. the columns are the correct height.