First, this is an AutoCAD newsgroup. There is another newsgroup specifically for AutoCAD Architecture that you probably should post these questions in.
Next, the most likely reasons you would not see the build panel are:
1) You launched ACA using an AutoCAD profile.
2) You used a workspace that did not include it.
Most of the ribbon is disabled when on the start tab BTW.
If you feel that the program installed incorrectly, do a repair or reinstall.
Architect, Registered NC, VA, SC, & GA.
