Proposed ADU and Garage
Project Details
This project involves the structural design and engineering of a two-story accessory dwelling unit (ADU) and attached garage totaling approximately 1,641 square feet. The comprehensive scope required modern engineering solutions for a wood-framed assembly, including the use of Douglas Fir Larch framing (No. 1 for beams and No. 2 for joists and rafters) integrated with structural plywood sheathing. The design incorporates specialized Hardy Frame (HFX) panels and a system of structural steel holdowns to ensure a durable and stable assembly capable of managing complex lateral loads. The design process included a rigorous structural analysis to ensure the residence could safely withstand environmental loads in accordance with the California Building Code (CBC 2022), IBC 2021, and ASCE 7-16 provisions. Special attention was given to lateral load resistance and seismic performance, as the project is engineered for Seismic Design Category D and wind speeds of 95 MPH (Exposure C). The foundation system features reinforced concrete continuous footings (2,500 psi minimum strength) designed to perform reliably under a gross soil bearing pressure of 2,000 psf. The ground floor assembly utilizes a 4-inch concrete slab supported by a 10-mil vapor barrier to manage moisture and expansive soil conditions. The scope of services includes the preparation of structural calculations and structural drawings for the proposed structure in accordance with applicable building codes and project requirements. Structural calculations shall include loading analyses for wind, seismic, dead, and live loads to determine the governing forces acting on the structure. The work shall encompass the structural analysis and design of all major structural components, including foundations, shear walls, load-bearing walls, columns, beams, headers, trusses or rafters, and all required connectors, ensuring a continuous and code-compliant load path capable of resisting both gravity and lateral loads.
Structural drawings shall include the plans and supporting details necessary for permitting and construction. The drawing set will consist of a Foundation Plan indicating the layout of the foundation system; a 2nd Floor Framing Plan and a Roof Framing Plan showing the arrangement and sizing of structural framing members; and Shear Wall Layout Plans for the 1st and 2nd floors identifying the location of lateral force-resisting elements. In addition, a Structural Building Section View will be provided to illustrate the vertical relationship and load transfer between structural components. The drawings will also include typical structural details, general structural notes, and technical specifications necessary to clearly communicate the design intent and support proper
Role
Structural Engineer/Designer
Services Provided
The scope of services included the preparation of structural calculations and structural drawings for the proposed structure in accordance with the applicable building codes and project requirements. Structural calculations included loading analyses for wind, seismic, dead, and live loads to determine the governing forces acting on the structure. The work encompassed the structural analysis and design of all major structural components, including foundations, shear walls, load-bearing walls, columns, beams, headers, trusses or rafters, and all required connectors, ensuring a continuous and code-compliant load path capable of resisting both gravity and lateral loads. Structural drawings included the plans and supporting details necessary for permitting and construction. The drawing set consisted of a Foundation Plan indicating the layout of the foundation system; a Second Floor Framing Plan and a Roof Framing Plan showing the arrangement and sizing of structural framing members; and Shear Wall Layout Plans for the first and second floors identifying the location of lateral force-resisting elements. In addition, a Structural Building Section View was provided to clearly illustrate the vertical relationship and load transfer between structural components. The drawings also included typical structural details, general structural notes, and technical specifications necessary to clearly communicate the design intent and support proper construction implementation while ensuring compliance with applicable codes and engineering standards.