Main Content


Once you’ve decided to build an Alley Flat, it is important to identify the neighborhood and planning specifications that may impact your project.

read more


Site Specifics:


Canterbury_active alley

Consider the placement of the Alley Flat on your site, its orientation, solar access, privacy, views, and your ideas for existing and future outdoor spaces. For example, consider your preferences on privacy and separation between the main unit and the Alley Flat, as well as between your Alley Flat and your adjacent neighbors. Also consider if you have any large trees on your property which might limit development (see the City of Austin’s tree regulations here.

Zoning Standards

Side yard setback:

5 ft (15 ft on a street side yard)

Rear yard setback:

10 ft (5 ft on an alley)

Maximum height:

30 ft /2 stories

Setback from principal structure:

10 ft minimum

Maximum lot coverage:

Building cover 40% max, Impervious cover 45% max

Parking spaces:

1 space required in addition to requirement for principal single-family house (if you are within 1/4 mile of an activity corridor as identified in the Imagine Austin Comprehensive Plan that is also served by transit no parking is required for the Alley Flat). The parking required for the principal single-family house is dependent on the codes in place at the time of construction of the principal house.


Per current code, ADUs must be less than 1,100 square feet or 15% of the lot area (whichever is smaller) and no more than 30 feet tall. The second floor of a 2 story ADU can be no more than 550 square feet.