New Year, New Casita


‘Accessory Dwelling Unit’ (or ADU for short) is the latest catchphrase in Austin – the city’s current ordinance relaxes building restrictions related to these backyard casitas. In 2016, the following changes to the ADU regulations were approved:

  • Reduce minimum lot size for ADUs on SF-3 zoned lots to 5,750 square feet.

  • Set the maximum size of an ADU to 1,100 square feet or 0.15 FAR, whichever is smaller

  • Reduce building separation to 10 feet (front to back and side to side).

  • Eliminate requirement that an entry be more than 10 feet from a property line.

  • Remove driveway requirement

  • Provide one parking space for the ADU in addition to main structure parking.

  • Eliminate parking requirement for ADU within 1/4 mile of an activity corridor as identified in the Imagine Austin Comprehensive Plan that is also served by transit

  • Limit use as short-term rental to a maximum of 30 days per year for ADUs constructed after October 1, 2015.

  • Prohibit use as a Type 2 short term rental.

This development tool has encouraged small-scale architecture and occupant longevity in central Austin properties. The accessory buildings we’ve designed have been variously used for occasional out-of town guests, elderly housing, studio or work space, music recording, therapy sessions, map storage, bicycle garage, printing press and photography.

Our latest project involving a secondary dwelling is in the Deep Eddy neighborhood. This property had an 1930 house that we fully intended to preserve, but fire code, heritage tree protection, and foundation rot led us to replace it completely. We developed a new house scheme based on this 915 square foot bungalow, with 2 bedrooms, 2 bathrooms, open living / eat-in kitchen, and laundry. With this tiny footprint, we were able to rotate and replicate the design on the rear of the lot, resulting in a set of twin houses (well, fraternal twins!). Unit A became the main house, and Unit B the ADU.


We were inspired by the many charming bungalows of the neighborhood, so we employed some familiar materials: cedar shakes in the gables, custom brackets, wide window trim with caps and sills, corner boards, and a nice overhang at the concrete porch. This is the house during construction last year:


The Zilker Hideaway has a 547 sf bike garage / workshop with 563 sf upstairs, and contains one bedroom, full bath, breakfast bar, living area, and desk nook.


The building has a stepped form so as to not crowd the main house or loom over the neighbor’s yard. With a backyard building, the resultant landscape area can be shaped for new uses, such as outdoor dining, garden tool storage, or a bocce court. An old stone wall on this site inspired our idea for the biergarten.


In a small building, rooms are proportioned so as to not feel cramped, but the smaller size allows for light to enter from all sides.


The Poolside Flat has 771 s.f. and contains two bedrooms (one used as a massage studio), full bath, galley kitchen, and living area.


Separating the approach to the pool house from the main house gives its visitors some discretion.


The pool house galley kitchen doubles as a hallway, so no circulation path is wasted.


The unit is designed to be fully accessible, with low thresholds , wide doorways, and, of course, no stairs.


Studio Outbuilding for Photography and Print has 470 s.f. downstairs, 170 s.f. upstairs and contains creative space, half bath, future shower, and computer desk space.


The studio outbuilding relieves the main house from the burden of work, and creative supplies can be arranged at arm’s reach.


A simplified building form contains a double height space over the make-table


This Bonnell Backhouse has a 528 s.f. garage and 307 s.f. upstairs suite for map storage, desk space, a tiny full bath, and covered deck.
The large sliding door transforms the garage during party-time.


Isn’t that stair kind of crazy? Kind of like a telephone booth lollipop.


The tiniest sink available made this 42″ wide full bath a possibility.


The ideas are brewing for more central Austin casitas!

Cindy Black