Condo - Duplex in South East Austin

[Asad Halai]

I recently acquired a 75 by 150 lot in South East Austin near Montopolis and 183. The area is up and coming. Never did a new build before so very excited about this project. Currently the lot has a tear down and we want to build a duplex (condo) so we can sell them seperately. The city does allow a duplex on this lot. The area can only warrant a max 100$ a sq/ft build out to make sense financially. I want to know how the process will work. 

a) Can plans be downloaded from the internet for a duplex?
b) Any other tips would be of great help!

Thanks