STRUCTURAL ENGINEERING FOR ADUs

Accessory Dwelling Units require safe, efficient structural systems that meet modern building and seismic code requirements. We provide complete structural design services for new detached units, attached additions, and garage conversions—delivering clear, permit-ready plans that ensure strength, stability, and long-term performance.

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Structural plans for construction

Structural Design for Safe and Code-Compliant ADUs

ADUs must safely transfer gravity and lateral loads from the roof and floors down to the foundation. Proper detailing of foundations, framing, and connections creates a continuous load path that allows the structure to perform reliably during everyday use and seismic events.

Our structural plans are prepared in accordance with current California Building Code requirements and local jurisdiction standards, helping streamline the permitting process while maintaining safety and efficiency.


Key Structural Systems and Components

Foundations

Foundations support the entire structure and distribute loads into the soil. We design slabs, footings, stem walls, and anchorage systems based on site conditions, building loads, and seismic demands.

  • Slab-on-grade systems
  • Spread footings and stem walls
  • Anchor bolts and hold-downs
  • Reinforcing steel detailing

Wood Framing

Efficient framing layouts provide strength while keeping construction practical and economical. Structural members are sized to safely resist gravity and lateral loads.

  • Floor and roof framing design
  • Beams and headers
  • Posts and load-bearing walls
  • Connection detailing

Lateral & Seismic Systems

Shear walls and hardware resist wind and earthquake forces, preventing excessive movement or damage during seismic events.

  • Plywood shear walls
  • Hold-down devices
  • Straps and collectors
  • Continuous load paths

Garage Conversions & Additions

Existing structures often require evaluation and strengthening to meet current standards. We design upgrades to foundations, walls, and framing to safely support the new use and layout.

Concrete foundation slab with reinforcing steel
Concrete slab-on-grade and footing foundation system.
Shear wall and framing connection detail
Typical framing and shearwall detailing.

Need Structural Plans for Your ADU?

Contact us to discuss your project and receive professional structural engineering support.

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