Structural and MEP design for an ADU over Detached Garage, San Diego, CA
This project involved the comprehensive engineering design for a new Accessory Dwelling Unit (ADU) constructed over a detached garage in San Diego, CA. S3DA Design provided a seamless integration of structural stability and modern MEP systems to transform a functional garage into a high-quality living space.
S3DA’s Scope:
- Structural Engineering: Comprehensive gravity, wind, and seismic load analysis per 2022 CBC and ASCE 7; design of foundation systems, garage-level framing, floor diaphragms, shear walls, and a complete permit-ready calculation package.
- Mechanical (HVAC): Detailed heat load reports, mechanical floor and roof plans, and refrigeration/condensate piping design.
- Electrical: Full lighting and power floor plans, single-line diagrams (SLD), and panel schedules tailored for residential efficiency.
- Plumbing: Domestic water and sanitary drainage systems, natural gas floor plans with isometric riser diagrams, and specialized roof rainwater design.
Key Challenges & Solutions: The primary engineering challenge was the vertical integration of a residential living space over an existing functional footprint. S3DA’s structural team engineered a robust framing system to support the second-floor ADU while maintaining the open spans required for the garage below. By acting as a Single Source of Responsibility, we eliminated the common coordination gaps between MEP and Structural teams, ensuring that plumbing risers and mechanical ducting were perfectly harmonized with the structural shear walls and floor joists.
The Result: S3DA delivered a fully coordinated, permit-ready set of drawings and calculations that strictly adhered to San Diego’s local building codes. The result is a value-engineered, energy-efficient ADU that maximizes property utility while ensuring long-term structural integrity and occupant comfort.
