From Austin-Bergstrom International Airport (~10 miles east of Downtown):
Take TX-71 W from the airport.
Merge onto I-35 North / US-290 E towards downtown Austin.
Exit 234A to Holly St.
Turn left onto Holly St, crossing I-35, and left again onto East Ave.
48 East Avenue will be on your right.

From Round Rock, TX (~20 miles north of Austin):
Get on I-35 S toward Austin.
Exit 234A toward Cesar Chavez St / Holly St.
Continue straight onto East Ave.
48 East Avenue will be on your right.