The Roundabout
Berkeley, California
Roundabout is a case study in how recent housing legislation can support not only additional units, but new forms of collective living. The project began with an existing duplex in South Berkeley owned by a group of people who had outgrown their previous co-op, the Radish in North Oakland. Their goal was not simply to add rental units, but to build a new community organized around shared space, long-term residency, and cooperative living.
The home showcases some of our signature design features: the entryway unfolds into a spacious, open living and dining area, with abundant natural light from the south-facing windows.
Details
- 1,600 exterior square feet
- Two-story layout
- Three bedroom, two-bathroom
- Full-size built-in kitchen
- Large attached balcony
The first commission was King, a backyard ADU. King was designed with a large kitchen and common living area on the ground floor and a two-bedroom apartment above, allowing it to function both as a dwelling unit and as a shared amenity for the larger household.
The project expanded when the group was able to purchase the vacant adjacent parcel. Rather than pursue a new single-family home, we advised that the parcel would be easier to permit and more aligned with recent state and local housing policy as a duplex. That project became Woolsey. Using Berkeley’s Missing Middle Housing Ordinance, the team received planning approval for Woolsey in one month.
Together, King and Woolsey add three new separate dwelling units to the existing two-unit property. The result is Roundabout: a five-unit residential community organized across two adjacent parcels, with shared outdoor spaces, common amenities, and multiple dwelling types serving a cooperative household structure.
The entitlement story for Woolsey is about sequencing. The project did not begin as a full missing-middle development. It began with an ADU behind an existing duplex: a relatively familiar infill strategy made possible by California’s ADU laws. The proposed ADU created one new unit, but also introduced shared amenities that supported the larger community.
When the adjacent vacant parcel became available, the entitlement opportunity changed. The project could have been framed as a new single-family home, but that path would have been less efficient and less consistent with Berkeley’s recent housing policy direction. A duplex was a better fit: it produced more housing, better matched the clients’ communal goals, and could proceed under Berkeley’s Missing Middle Housing Ordinance.
That ordinance became the key regulatory pathway. By designing the new building as a duplex rather than a single-family home, the project aligned with an approval framework intended to make small multifamily housing more feasible in residential neighborhoods. Planning approval was received in one month, demonstrating the practical value of a clear local missing-middle pathway.
The final entitlement strategy layers multiple infill tools. The existing duplex remains. The ADU adds one new dwelling unit and shared amenities. The adjacent parcel becomes a new duplex with two additional units. Rather than relying on a single law or one isolated building type, Woolsey uses a combination of ADU law, local missing-middle legislation, and parcel acquisition to create a larger residential community.
The client story is central to Woolsey. The owners are a group of people who had outgrown their previous home, a co-op called the Radish in North Oakland, and were looking to build a new intentional community in South Berkeley. Their housing need was not simply more bedrooms. They needed a physical framework for shared living: private dwellings, common gathering spaces, outdoor amenities, and enough flexibility to support a larger group over time.
The backyard ADU was designed to serve this dual role. Its upper floor provides a two-bedroom apartment, while the ground floor contains a large kitchen and common living area for the broader community. The ADU is therefore both housing and infrastructure: a new dwelling unit and a shared domestic center.
The later duplex expands that community. It includes one larger three-bedroom home and one ground-floor two-bedroom apartment, adding multiple household configurations to the site. These units allow the community to support different residents, household sizes, and degrees of privacy while remaining connected through shared outdoor areas and amenities.
The roof deck on the ADU, with a hot tub and outdoor shower, reinforces the project’s social logic. It is not a conventional backyard accessory. It is part of the collective life of the site: a shared outdoor room that gives the community a place to gather, relax, and maintain the informal social rituals that make cooperative housing work.
