This project involves the structural engineering design of a new Accessory Dwelling Unit (ADU) constructed above an existing car garage in San Diego. The scope focuses on ensuring the existing garage structure can safely support the additional vertical and lateral loads associated with the new upper-level residential unit, while meeting current California Building Code and local jurisdiction requirements.
Structural calculations and analysis include comprehensive load evaluations for seismic, wind, dead, and live loads, reflecting San Diego’s seismic design criteria. Our engineering team performed a detailed structural analysis and design of all elements associated with the new ADU, including:
- Verification and strengthening (as required) of existing foundations and footings
- Analysis of garage slab and walls to confirm load transfer capability
- Design of new columns, beams, and floor framing systems
- Evaluation and design of load-bearing walls and shear walls
- Roof framing and diaphragm design for gravity and lateral load resistance
- Design of hold-downs, connectors, and full load path continuity
In addition, a structural evaluation of the existing garage framing and foundation was completed to confirm adequacy for the new ADU loads. Where deficiencies were identified, targeted strengthening solutions were designed to ensure safety, performance, and constructability.
This project delivers a code-compliant, efficient, and build-ready structural solution that supports vertical expansion while maximizing the use of existing structures—an ideal approach for urban infill and ADU development in Southern California.
