By the way, I was looking at the permit for the cranes, and on the diagram for the building it shows the building sections labeling the floor counts of each. Anyway, for the main tower - the 9-story section facing Red River Street, it notes that there is a plan for a "4-story future expansion." So they may be planning to add 4 more floors to the main tower eventually for a total of 13 floors facing Red River Street. Of course there is an extra floor on the west side of the building facing Waller Creek. If you look at the renderings, it does appear to be designed so that more floors could be added. In fact, most several of the buildings appear that way.
Right now the 10th floor of the building is planned to be 147 feet above the street. Right now the breakdown is 147 feet / 10 floors = 14.7 feet per floor. So 4 more floors would be another 58.8 feet. That would push the top floor height to 205 feet. Above that is the mechanical penthouse, which if they maintain the same scale and design as it is today, that would push the height to 220 feet.
That image also shows the routes of the capitol view corridors around the building.
ftp://ftp.ci.austin.tx.us/ATD_AULCC/...rane_PLANS.pdf