Proposed Accessory Dwelling Unit
Project Details
This project involves the structural design and engineering of a proposed Accessory Dwelling Unit (ADU) with a total liveable floor area of 478 sq. ft. The comprehensive scope required modern engineering solutions for the entire assembly, including an engineered steel tube structure integrated with high-strength aluminum framing components utilizing 6061-T6 and 6063-T6 aluminum alloys. The building envelope features typical wall assemblies composed of sheet aluminum in extruded aluminum frames with 5-1/2″ rigid EPS insulation, while the roof is constructed of 4″ poly-iso insulated metal panels. The design process included a rigorous structural analysis using finite element modeling to ensure the unit could safely withstand various environmental loads. The structural elements were engineered in accordance with ASCE 7-16, AISC 360-16 for steel, and ACI 318-19 for concrete provisions. Special attention was given to lateral load resistance and stability requirements for Seismic Design Category D and design wind speeds of 110 MPH. The foundation system features reinforced concrete stem walls, independent pad footings, and strip wall footings designed to perform reliably under a soil bearing capacity of 1,500 psf.
Role
Structural Engineer/Designer
Services Provided
The scope of services includes the preparation of comprehensive structural calculations and structural drawings for the proposed structure, including all associated deck areas. Structural calculations shall include complete loading analyses for wind, seismic, dead, and live loads, as applicable to the project site and governing building code. The work shall encompass the structural analysis and design of all primary and secondary structural components, including foundations, footings, grade beams, slabs (as applicable), columns, beams, girders, braces, rafters, joists, deck framing members, and all required connections to ensure a continuous and code-compliant load path. Design services shall also include lateral force-resisting systems, uplift and overturning checks, diaphragm analysis (floor and roof), drift evaluation, and connection design necessary to support gravity and lateral demands.
Structural drawings shall include a Foundation Plan identifying footing and foundation layout with anchor bolt, reinforcing, and tie-down schedules; Floor Framing Plans for all levels, including deck framing layouts and connection requirements; a Roof Framing Plan indicating rafters, beams, bracing, and diaphragm components; and Framing Elevations per gridline to clearly communicate vertical load paths and member sizing. The drawing set will further include structural details, sections, connection details, general structural notes, and technical specifications necessary for permitting, coordination, and construction. All documents shall be prepared to provide clarity for plan review and field implementation while ensuring compliance with applicable codes and project requirements.