Structural Engineering in the United States

The US Structural Engineering Code Framework

Structural engineering in the United States is governed by an integrated hierarchy of codes. ASCE 7-22 (Minimum Design Loads and Associated Criteria for Buildings and Other Structures) defines wind, seismic, snow, flood, and live load requirements. AISC 360-22 covers structural steel design using the LRFD and ASD methods. ACI 318-19 governs reinforced and prestressed concrete design. The International Building Code (IBC) 2021 — adopted in whole or with amendments by most US states — provides the regulatory framework that references these standards and sets occupancy, fire, and accessibility requirements.

Most US states have adopted IBC 2021, frequently with state-specific amendments. The most notable state amendment is the Florida Building Code (FBC), which supplements IBC with Florida's hurricane-specific wind provisions. California's Building Code (CBC) applies the IBC framework with substantial seismic amendments based on ASCE 7-22 Chapter 11–22, reflecting California's high seismicity. Texas and the Gulf Coast states apply FBC-comparable wind provisions in coastal exposure zones.

ASCE 7-22: Loads That Govern US Design

ASCE 7-22 is the load standard at the heart of US structural engineering. Key provisions that distinguish ASCE 7-22 practice include:

• Wind loads (Chapter 26–31) — Risk-category-based design wind speeds with updated Ultimate Design Wind Speed (V) maps for all US regions. Exposure categories A–D based on terrain roughness. Pressure coefficients for enclosed, partially enclosed, and open buildings. Component and cladding pressures (C&C) often govern cladding design even where main wind force resisting system (MWFRS) loads are modest.
• Seismic loads (Chapters 11–22) — Spectral acceleration maps (SS and S1) based on USGS national seismic hazard maps. Site-class-adjusted design spectral parameters (SDS and SD1). Seismic Design Categories (SDC A–F) that determine permitted structural systems and detailing requirements. Special Moment Frames, Special Concentrically Braced Frames, and other seismic force-resisting systems per AISC 341-22 are required in SDC D–F.
• Snow loads (Chapter 7) — Ground-to-roof snow load conversion with exposure factor, thermal factor, and importance factor. Drift load at parapets and higher roofs. Sliding snow loads on sloped roofs. Unbalanced snow on hip, gable, and curved roofs.
• Load combinations — LRFD load combinations per ASCE 7-22 Table 2.3.1, including seismic load combinations with overstrength factor (Ω0) for non-ductile connections and compression-controlled members.

Florida Building Code: Hurricane Engineering

The Florida Building Code 2023 (FBC) is the most stringent hurricane wind design code in the United States. Florida's exposure to Atlantic and Gulf of Mexico hurricanes has driven FBC wind speed maps that show Ultimate Design Wind Speeds (V) significantly higher than the base ASCE 7-22 Risk Category II map in most Florida locations. Key FBC provisions include:

• High-Velocity Hurricane Zone (HVHZ) — Miami-Dade and Broward counties are designated HVHZ. Structural connections, cladding, glazing, and roofing systems in HVHZ must meet the Florida Product Approval System requirements, with testing and product approval numbers required on the construction documents.
• Design wind speed mapping — FBC provides county-specific wind speed maps, and many Florida coastal areas have design wind speeds of 150–170 mph. Inland Florida still requires 130–140 mph design in most Risk Category II occupancies.
• Roof-to-wall connections — FBC requires prescriptive or engineered uplift connection capacity for all roof-to-wall and wall-to-foundation connections, with minimum uplift values per the FBC wind speed map and roof zone calculations.

Our Florida waterslide supports project (Project P-2023-072) required full HVHZ-adjacent wind design with combined vertical loading from water weight, rider live load, and hurricane wind pressures. AISC 360-22 member design and FBC/IBC load combinations were applied throughout.

US Project: Florida Waterslide Steel Supports

Project P-2023-072 is our primary US structural commission. The engagement required structural design of steel support frames for waterslide structures in a Florida location requiring FBC wind load compliance. The project scope included:

• Wind load derivation per FBC 2020 (applicable at time of design), including pressure coefficients for the open-frame support geometry
• Combined loading: dead load, water weight, rider live load, and wind pressure interaction
• AISC 360-22 LRFD member design for hollow structural sections (HSS) and wide-flange columns
• Bolted connection design per AISC 360-22 Chapter J, with slip-critical bolts at critical exposed-environment joints
• Foundation design for combined vertical and uplift loads with soil-structure interaction
• Documentation formatted for Florida PE review and building permit submission

How We Work with US Clients

Sixteens Consultancy Services operates as a structural engineering sub-consultant for US projects. This is a common and well-established arrangement: we provide the full structural engineering design and calculations, and the US-licensed Professional Engineer (PE) of record reviews, takes professional responsibility for, and stamps the drawings for building department submission.

The process for a US project engagement:

• Step 1: Brief — Client shares architectural drawings, site address (for ASCE 7-22 wind and seismic parameters), applicable code edition, PE-of-record information, and any AHJ-specific requirements.
• Step 2: Scope confirmation — We confirm applicable codes, identify any special conditions (HVHZ, SDC D+, coastal exposure), provide fee and timeline.
• Step 3: Design — Full structural engineering: load derivation, member design, connection design, foundation design. Analysis in ETABS or SAP2000 for complex structures.
• Step 4: Delivery — Structural calculations (PDF/Word with explicit code citations), structural drawings (DWG/PDF), design report.
• Step 5: PE review support — We provide clarification responses, calculation amendments, and drawing revisions during the PE review and building department review process.

Cities We Serve in the United States

We provide structural engineering services for projects across all major US cities and states:

• New York City — NYCBC 2022, ASCE 7-22, high-rise steel frames, progressive collapse provisions, SDC B seismic detailing
• Los Angeles — CBC 2022, ASCE 7-22, SDC D/E high-seismic design, Special Moment Frames, BRBF systems, soft-story retrofit
• Houston — IBC 2021, ASCE 7-22 Wind Zone III, hurricane wind engineering, PEB industrial structures, expansive clay foundations
• Miami — FBC 2023, ASCE 7-22, HVHZ extreme wind design, concrete capacity assessment, coastal corrosion-resistant design