So I'm still not sure if this is the same project as the one being called Huston Heights. The Austin City Center one is said to be located at the northeast corner of East 12th & I-35, but the Huston Heights one is listed on the Emerging Projects list as being at the southeast corner.
ftp://ftp.ci.austin.tx.us/DowntownAu...2015-05-31.pdf
This is the Huston Heights development.