Accessory Dwelling Units

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What is an accessory dwelling unit (ADU)?

A habitable dwelling unit detached from a single-family dwelling, on a permanent frost free foundation, connected to sanitary sewer and water services, that provides basic requirements for living, sleeping, eating, cooking, and sanitation and conforms to applicable building codes.


  • ADU’s are listed as accessory structures in our Land Development Code.
  • One ADU is allowed per lot, you can have up to 3 accessory structures on your lot.
  • Churches and all residential zoning districts are allowed to have ADUs.
  • ADUs are not subject to the 20% rental density restriction.
  • ADUs do not count towards the allowed amount of lot coverage.
  • ADUs can be located as part of a detached garage or can be their own separate structure. If the ADU is part of a garage, then the garage regulations should be followed. 
  • Limit on size: cannot exceed 50% of the gross floor area of the main home or 1,000 square feet, whichever is less.
  • Constructed to be compatible with the main home and neighborhood.
  • Must be at least 10 feet from the main home.
  • Parking is not required, but have to provide unrestricted, improved access must be provided from the street to the ADU entrance.
  • Must have a kitchen, bathroom, sanitary and water services.
  • The ADU or main home may be rented if the owner of the property lives resides on the property.

Read more about the ADU regulations in the City's Land Development Code.

Application Process

To apply for an Accessory Dwelling Unit, a building permit is required. A set of building plans and a Certificate of Survey would be required.

Learn more about building permits and inspections

Submit a building permit

If you want to rent out an ADU and the requirements are met, a rental license can be obtained. 

Learn more about rental licenses 


Accessory Dwelling Units: Model State Act and Local Ordinance - AARP (PDF)

Making Big Sense of Small Homes - AARP

Knowledgebase Collection: Accessory Dwelling Units - American Planning Association

Model Code for Accessory Dwelling Units - American Tiny House Association

As housing costs and economic segregation increase, Austin’s granny flats proliferate - The Architects Newspaper

The Granny Flats Are Coming - CITYLAB

How One Colorado City Instantly Created Affordable Housing - CITYLAB

Accessory Dwelling Units - City of Austin, TX

Seattle’s New Environmental Study on Accessory Dwellings Obliterates Obstructionists’ Claims - Sightline Institute

Washington Just Advanced the Nation’s Best ADU Reform. Here’s Why It’ll Help. - Sightline Institute

Jump Starting the Benefits of ADUs in Minneapolis - Streets MN

The 5 Immutable Laws of Affordable Housing - Strong Towns