Proposed SFD Renovation

Project Details

This project involves the structural analysis and engineering for the renovation and expansion of a single-family dwelling. The comprehensive scope includes a total proposed building footprint of 4,020 sq. ft., consisting of a primary residence (2,460 sq. ft.), a new Accessory Dwelling Unit (ADU – 610 sq. ft.), a Junior ADU (JADU – 500 sq. ft.), and a 450 sq. ft. two-car garage. The engineering solutions covered the entire structural assembly, including roof joists, floor joists, rafters, beams, and columns. The primary structure utilizes a sophisticated mix of materials, including Douglas Fir-Larch sawn lumber (No. 1 and No. 2 grades), Weyerhaeuser TJI® engineered wood joists, and structural steel columns (HSS 7.5×3/8″ A500 Gr. C). The design process utilized a rigorous loading analysis performed in accordance with the International Building Code (IBC 2021), California Building Code (CBC 2022), and ASCE 7 provisions. Special attention was directed toward lateral load resistance through a comprehensive shear wall system. This system utilizes 15/32″ Structural-I plywood sheathing integrated with specialized Simpson Strong-Tie hardware, such as HDU series hold-downs, to ensure stability against a design wind speed of 96 MPH and rigorous requirements for Seismic Design Category D. The foundation system features independent reinforced concrete pad footings (ranging from 1.5’x1.5′ to 2.5’x2.5′) and concrete stem walls designed to perform reliably under a gross soil bearing pressure of 1.5 ksf.

Role

Structural Engineer/Designer

Services Provided

The scope of services included the preparation of structural calculations and structural drawings necessary for the structural design and documentation of the proposed project. Structural calculations included complete load analyses for wind, seismic, dead, and live loads based on applicable building codes and site conditions. The services also covered the structural analysis and design calculations of all structural components, including but not limited to foundations, shear walls, columns, beams, floor joists, headers, rafters or trusses, connectors, and other related structural members required to ensure a safe, stable, and continuous load path throughout the structure.
Structural drawings were developed to clearly communicate the structural layout and construction requirements. The drawing set included a Foundation Plan indicating the layout and configuration of the foundation system; Second Floor Framing Plans showing the arrangement of beams, joists, and supporting members; and Roof Framing Plans identifying rafters, trusses, and associated roof structural elements. The drawings also included First Floor and Second Floor Shear Wall Layout Plans indicating the location and extent of the lateral force-resisting system. In addition, the set provided typical structural details, general notes, and specifications necessary to guide construction, coordination, and permitting while ensuring compliance with applicable codes and the structural design intent.