Berkeley Hills ADU: A Multi-Generational Addition
DSA Architects took on an accessory dwelling unit project in the Berkeley Hills for a family seeking a long-term multi-generational living solution. The site presented real challenges — steep topography and limited yard space meant a conventional ground-level ADU wasn't a viable option. Instead, the ADU contractor team shaped the unit as an 850 sq. ft. second-floor addition, carefully matching existing building materials and volumes so the new structure integrates naturally with the existing home.
The result is a 2-bedroom, 1-bath accessory dwelling unit that feels like a considered part of the original structure rather than an afterthought. The interior features an open living, dining, and kitchen layout, with a generous window wall that opens up to views of Tilden Park and a large Deodar Cedar tree directly outside — giving the space a distinctive treehouse-like quality. A roof deck extends the living experience outdoors, offering panoramic views of the hillsides to the east.
Sustainable Systems and Energy Efficiency
The detached ADU builder approach here extended beyond just the physical structure. The unit was designed with sustainability in mind. A new solar PV system on the roof powers the dwelling, while both domestic hot water and space heating are handled by heat pumps. Recovery ventilation was incorporated to support energy conservation and improve indoor air quality. The new shower was also plumbed for gray-water diversion into the yard, reducing overall water consumption.
These systems reflect a practical approach to building an in-law suite or secondary dwelling that performs well over time, not just at the point of completion.
Construction Complexity and Compliance
The construction of this ADU builder project was handled by General Contractor Julio Sanchez of Universal Construction. The build involved navigating fire zone requirements specific to the Berkeley Hills, as well as meeting stringent sound separation criteria between the two dwelling units — both of which added layers of complexity to an already technically demanding project on a steep hillside lot.
DSA Architects managed the design and coordination of this project from concept through to completion, demonstrating their experience working within challenging site conditions and local regulatory requirements to deliver a functional accessory dwelling unit suited to multi-generational living.
