That's right, for some reason I was thinking it was 2 more floors. The hotel today has 15 floors, so it makes sense that if they had to first demolish the 11th floor (old ballroom floor) then add the 5 floors that it would come out to 15.
T.B. Baker was also responsible for building the Baker Hotel in Mineral Wells, which I believe is one of the grandest old building in Texas.
https://thebakerhotel.wordpress.com/category/t-b-baker/