Preventing Structural Failures Through Improved Communication of Design Intent
Recent Revisions to the AISC Code of Standard Practice for Steel Construction
Prevention of structural failures is an objective that contractors, design professionals, owners, developers, steel fabricators, sureties, and construction insurers all share. Just this week an apartment building in Davenport, Iowa, partially collapsed raising concerns about persons who may be trapped inside, and the safety of those who are attempting to perform search and rescue operations in the unsound structure.
Other recent deadly structural failures such as the April 18, 2023, parking garage collapse in New York City, and the June 24, 2021, condominium collapse in Florida are stunning reminders that the risk of such failures still exists, and can be catastrophic. The likelihood of structural failures increases significantly when the engineer of record’s structural design is not clearly communicated to the parties who will be executing the design. For years the American Institute of Steel Construction (“AISC”) has worked diligently to reduce the risk of structural failures through improvements to its Code of Standard Practice for Steel Buildings and Bridges (“CoSP”). In November 2022, the AISC published its most recent revised edition of the CoSP with key revisions that should improve the clarity and flow of structural design documents from the engineer of record to the construction team.
Structures fail for a variety of reasons, such as construction defects, deferred maintenance, design flaws, natural disasters, and terrorist attacks. For example, initial investigations attribute the recent New York parking garage collapse to the building’s age, code violations, poor maintenance, and possible overloading caused by electric vehicles that are substantially heavier than gas powered vehicles. Whereas, deteriorated reinforced concrete, combined with the failure to implement a structural engineer’s remediation plan, led to the collapse of the Surfside, Florida, condominium tower in 2021 resulting in the deaths of 98 people. However, it was a communication breakdown between the engineer of record and the construction team that caused the most deadly building collapse in the United States (not including the 9/11 terroristic attacks), which occurred on July 17, 1981, when three suspended walkways inside the Kansas City Hyatt Regency Hotel collapsed killing 114 people.
On the Hyatt project, the structural engineer of record (“EOR”) provided a conceptual sketch illustrating the suspended walkways supported by steel rod hangers to be attached to the roof trusses. Without providing a design for the steel connection, the EOR provided the conceptual configuration to the steel fabricator, who recognized that it could not be built as depicted. In order to design a steel connection that could actually be assembled in the field, the fabricator modified the EOR’s configuration, and submitted a shop drawing to the EOR showing that modified configuration. The EOR who believed that the fabricator was responsible for the connection design, approved that shop drawing without fully reviewing the structural adequacy of the reconfigured connection.
However, since the EOR was legally responsible for overall structural design of the project, the fabricator relied upon the EOR’s approval of the shop drawing and fabricated the steel, which was eventually erected using the reconfigured connection. After the hotel opened, the walkways collapsed because the reconfigured steel rod connections could not support the load of a large gathering of people attending a hotel event. In the aftermath of that catastrophic structural failure, the AISC revised its CoSP to establish standardized best practices to improve communication of design intent and delegation of design responsibility from the structural engineer of record to the project team.
In 1924, AISC first published its CoSP to standardize code practices relating to structural steel design and construction. AISC periodically revises the CoSP to reflect current trends in project delivery, evolving technology, and construction practices based on AISC’s surveys of the structured steel design community and construction industry. As such, the CoSP reflects a consensus of custom and usage for fabricated structural steel.
In November 2022, AISC released its latest revised version of the CoSP. Section 3 titled “Design Documents and Specifications,” adds clarity to the process for transmitting the responsible engineer’s design intent to the project team members who will be executing the design. Those revisions strive to better inform the users of structural design documents of their intended usage based on how the documents are published and who publishes them. The revisions explain the distinctions between design documents that are ISSUED versus those that are RELEASED. Design documents can only be ISSUED by the Owner’s Designated Representative for Design (“ODRD”), whereas design documents can be RELEASED by an Owner, Construction Manager, or other party. The CoSP Section 3 revisions also require the preparers of design documents to state on the face of the documents the intended purpose for those documents.
The 2022 edition of the CoSP also introduces and defines terminology that design professionals should use to designate and distinguish the purposes for which various iterations of design documents are intended to be used. Those design document designations are:
RELEASED FOR CONSTRUCTION – Identifies design documents provided by the owner, construction manager, or general contractor to the steel fabricator. They contain the complete structural steel design, even though the architectural, mechanical, or electrical designs may not be complete, as is usually the case with fast-track projects. The steel fabricator can use these design documents to order, detail, and fabricate steel for the project.
RELEASED FOR OTHER DESIGNATED PURPOSES – Identifies design documents that can be provided by the owner, construction manager, or general contractor to a cost estimator, construction manager, or general contractor for bidding, cost estimating, establishment of a guaranteed maximum price, or other designated use.
ISSUED FOR CONSTRUCTION – Identifies fully completed design documents issued and sealed by the ODRD that can be used for construction.
ISSUED FOR OTHER DESIGNATED PURPOSE – This identifies design documents issued by the ODRD to the building permit authority, general contractor, construction manager, or cost estimator. These documents can be used for bidding, estimating, design coordination, plan review for permitting, or other designated purposes.
Section 3.1 of the 2022 CoSP requires design documents that bear the designation ISSUED FOR CONSTRUCTION to provide the detailed design information listed in section A4 of the 2022 AISC Specification for Structural Steel Buildings (“Specification”), including loads for steel members, connection designs, moment connections, etc. Section 3.1 of the CoSP also prescribes detailed painting requirements for structural steel. The revised CoSP allows the ODRD to delegate connection designs to a licensed engineer employed by the fabricator. It also permits the ODRD to designate connections to be selected by an experienced steel detailer from standard connections contained in reference materials included in the design documents. These clarified design requirements should prevent the type of design ambiguity and delegation of design missteps that led to the collapse of the Kansas City Hyatt Hotel.
The adherence to the revised design document provisions in the 2022 CoSP should significantly decrease the risk of design-related structural failures in the future. However, it is reasonable to question whether design professionals are legally obligated to abide by CoSP requirements. Fortunately, the 2022 revised CoSP strengthens the legal enforceability of the CoSP’s specific design document requirements.
Section 1.1 provides that the entire CoSP applies to all structural steel projects, and that any contrary instructions by a design professional will only be permitted if they do not violate the applicable building code or a contract provision. Section 3.1 of the CoSP goes even further by incorporating design requirements set forth in the Specification, which is fully incorporated into the International Building Code (“IBC”). Those CoSP provisions that have been incorporated into the universally adopted IBC now carry the force of law, such that a failure to comply with those provisions will constitute a building code violation. This revision essentially mandates compliance with the CoSP design requirements by greatly enhancing their legal enforceability. Historically, the CoSP became legally binding on the project participants ONLY if it was incorporated into the contract documents or required by the applicable building code. Consequently, this 2022 revision that makes portions of the CoSP part of the IBC significantly elevates legal enforceability to reduce the risk of structural failures.
In addition to the design document requirements discussed above, the 2022 edition of the CoSP contains many other significant revisions, which merit an in-depth review by all participants in the structural steel fabrication and construction industry.