What Is an ADU and Why Consider Building One?
Accessory Dwelling Units (ADUs) — sometimes called granny flats, in-law units, or backyard cottages — are secondary residential units with their own address that can be rented out independently. They typically range from 300 to 1,200 square feet, can be up to two stories tall, and in many cases allow homeowners to eliminate parking or garage requirements.
For single-family homeowners, building a detached ADU in the backyard or completing a garage conversion can open up a range of practical options:
- Personal use: Extend living space, create a home studio or office, or activate an underused yard.
- Family and guests: House relatives, host guests, or establish a multi-generational living arrangement.
- Rental income: Rent the unit out for additional income or as part of a longer-term financial plan.
Regardless of how the space is used, adding an ADU generally increases property value. In many cases, the unit can pay for itself in under ten years.
Bunch Design's Approach to ADUs in Los Angeles
Bunch Design is a Los Angeles-based firm offering both custom ADU design and a selection of pre-designed ADU options. Their pre-designed units are not prefabricated — they are standard stud-framed buildings that the firm has constructed multiple times, which helps streamline both the design process and cost estimation.
Unlike prefab units, which are constrained by transport dimensions and offer limited customization, Bunch Design's pre-designed options can be adapted to a significant degree. They note that prefab units have not consistently come in at a lower cost than their pre-designed alternatives, while also offering less flexibility in layout and use.
Their pre-designed ADU lineup currently includes four options, each with defined specifications and a known price range:
Garage Studio ADU
This is Bunch Design's most popular pre-designed unit, suited for clients looking to replace or convert an existing garage into a livable space. Several variations have been built, ranging from 300 to 500 square feet, with open studio or one-bedroom layouts. All versions include full amenities such as washer/dryer, refrigerator, dishwasher, and HVAC.
- Studio or One Bedroom, 1 Bath
- Area: 300–600 sf | Footprint: 20' x 20' typical
- Starting price: $300K+
Cottage ADU
A split-level design intended for sites with some change in grade. The one-bedroom, one-bath layout creates a cabin-like atmosphere with a contemporary feel. A clear Douglas fir ceiling emphasizes the linear form of the structure and contributes to a sense of spaciousness.
- 1 Bed, 1 Bath | Area: 750 sf | Footprint: 13' x 44'
- Starting price: $400K+
Stop Making Sense ADU
This two-bedroom unit has received an AIA Merit Award and was shortlisted by Dezeen. It features wood trusses, clerestory windows, and sliding panel walls that divide the interior space. Large glass sliding doors connect the living area to exterior side yards.
- 2 Bed, 1 Bath | Area: 820 sf | Footprint: 19' x 52'
- Starting price: $425K+
Step ADU
A two-bedroom unit with a stepped ceiling and clerestory windows that bring natural light throughout. The design includes skylights and a separated wet bathing room and toilet room. Previously built versions include an 880 sf unit completed in 2018 and a 950 sf version completed in 2022.
- 2 Bed, 1.5 Bath | Area: 880 sf | Footprint: 23' x 40'
- Starting price: $425K+
Note: Listed prices do not include design fees, utility hookups, landscaping, or upgrade features.
Custom ADU Design
In addition to their pre-designed lineup, Bunch Design also offers fully custom ADU design for clients whose site or program requirements fall outside the pre-designed options. Both paths — custom and pre-designed — are available through the firm, giving homeowners in Los Angeles a range of entry points depending on their budget, timeline, and design goals.
