Hi, According to the Austin MLS listing information, the lot is 50' x 136' or 6,800 square feet / 0.158 acres. This home is in Hyde Park which is one of the most popular neighborhoods in central Austin, so all construction activities will have to comply with the City of Austin and Travis County permitting rules and regulations as well as the additional rules that the Hyde Park Neighborhood Association has for this property. Although this property does appear to be inside the Hyde Park Historic District boundaries, the rules of the Hyde Park Neighborhood Association may still apply. I would recommend checking with them to make sure any building activities are in compliance with their rules.
Let me know if you would like to go take a look at this property.
Here are some of my websites: