ADU Addition to Existing Garage in Crocker Highlands, Oakland
Kaplan Architects completed an accessory dwelling unit project in the Crocker Highlands neighborhood of Oakland, adding a new ADU to the rear of an existing detached garage on a hillside lot. The project presented a specific site challenge: how to introduce a new living space on a sloped lot without sacrificing the usable level patio area that the property already offered.
To address this, the design team chose to partially bury the addition into the hillside. This approach preserved the patio space while still allowing for a functional and well-integrated structure. Considerable effort went into ensuring the new ADU connected visually and structurally with the existing garage, rather than appearing as a disconnected addition.
Design Approach and Layout
Privacy between the main house and the new accessory dwelling unit was treated as a key priority throughout the design process. The exterior of the ADU was designed to reference the Tudor style of the primary residence, while the interior takes on a more contemporary aesthetic.
The interior layout was planned to serve multiple purposes. The owners intended to use the unit as:
- A home office
- An exercise studio
- An occasional guest room
ADU regulations in most jurisdictions permit this kind of personal use, and Kaplan Architects factored this flexibility into the design. At the same time, the layout was also considered with rental use in mind, so the unit can function well as a standalone rental space if needed.
Interior Details
The finished interior space totals 280 square feet, consisting of a 10.5' x 13' main room with a kitchenette and a full bathroom. A raised ceiling in the main room helps the relatively compact space feel more open and less confined.
Kaplan Architects handled the interior design in full, including the selection of all finishes and the lighting design — an approach consistent with how they manage most of their projects.
This project is a practical example of how a detached ADU builder can work within challenging site conditions — such as a hillside lot with limited flat space — to deliver a unit that meets both the functional needs of the homeowner and the requirements for potential rental use.
