ANSI/AISC 303: Code of Standard Practice – What Changed from 360-16 to 360-22

ANSI/AISC 303 – the Code of Standard Practice for Steel Buildings and Bridges – is the contractual and procedural framework for structural steel construction in the United States. It defines the standard practices and responsibilities of the owner, the engineer of record (EOR), the fabricator and the erector. It covers the shop drawing process, the mill material certification requirements, the erection tolerances, the procedures for handling errors and omissions and the division of responsibility between the parties involved in structural steel construction.

AISC 303 is updated in conjunction with AISC 360. The 2022 edition of AISC 303 (AISC 303-22) was published alongside ANSI/AISC 360-22 and supersedes the 2016 edition (AISC 303-16). Understanding what changed between the two editions – and what stayed the same – is essential for contractors, fabricators and erectors working on projects designed to ANSI/AISC 360-22.

This post covers what AISC 303 is, how it relates to AISC 360, what changed between the 2016 and 2022 editions, and what those changes mean for the construction methodology, the programme and the Efficient Construction Cost (ECC).

What AISC 303 Is and Why It Matters

AISC 303 is not a design standard. It does not define how structural steel is designed. It defines how structural steel construction is organised, managed and executed. It answers the questions that AISC 360 does not: who is responsible for what, what is included in the fabricator’s scope by default, what is included in the erector’s scope by default, what the shop drawing process looks like, what the erection tolerances are and what happens when something goes wrong.

AISC 303 is frequently incorporated into structural steel subcontracts by reference. When a subcontract says “the work shall be performed in accordance with the AISC Code of Standard Practice,” it means AISC 303. Every contractor, fabricator and erector working on structural steel in the USA should be familiar with AISC 303. It defines their obligations and their rights.

The relationship between AISC 360 and AISC 303 is straightforward. AISC 360 defines the technical requirements – the strength, serviceability and stability requirements that the design must meet. AISC 303 defines the procedural requirements – the process by which the design is translated into fabricated and erected steel. Both must be complied with. A project that meets the technical requirements of AISC 360 but does not follow the procedural requirements of AISC 303 is not in compliance with the standard of practice for the industry.

Structure of AISC 303

AISC 303 is organised into sections covering the key aspects of structural steel construction. The main sections are:

Section	Title	Key Content
1	General Provisions	Scope, definitions, referenced standards
2	Classification of Materials	Standard structural steel materials and their classification
3	Design Drawings and Specifications	What the EOR must show on design drawings – minimum information requirements
4	Shop and Erection Drawings	Shop drawing production, submission, review and approval process
5	Materials	Mill certifications, material identification and traceability
6	Fabrication	Fabrication tolerances, standard fabrication practices, what is included in the fabricator’s scope
7	Erection	Erection tolerances, standard erection practices, what is included in the erector’s scope
8	Quality Control and Quality Assurance	QC and QA requirements, inspection, AISC Certification
9	Contracts	Contract requirements, changes, errors and omissions
10	Architecturally Exposed Structural Steel (AESS)	Additional requirements for exposed structural steel

What Changed from AISC 303-16 to AISC 303-22

The 2022 edition of AISC 303 includes a number of significant changes from the 2016 edition. The changes reflect developments in industry practice, technology and the lessons learned from the application of the 2016 edition. The key changes are described below.

1. Digital Delivery and Electronic Processes (Section 4)

One of the most significant changes in AISC 303-22 is the formal recognition of digital delivery and electronic processes throughout the shop drawing and approval workflow. The 2016 edition was written primarily with paper-based processes in mind. The 2022 edition explicitly addresses the digital reality of current industry practice.

Key changes in this area include:

Electronic submission and approval of shop drawings – AISC 303-22 formally permits shop drawings to be submitted and approved electronically. The standard defines the requirements for electronic approval – the approval must be traceable, the approver must be identified and the date of approval must be recorded. This formalises what has been common practice for many years but was not explicitly addressed in the 2016 edition.
Digital signatures – the 2022 edition recognises digital signatures as a valid means of approving shop drawings, provided the digital signature meets the requirements of applicable law and the contract documents.
Electronic document management – the 2022 edition acknowledges that shop drawings and other project documents are typically managed through electronic document management systems (EDMS). The standard does not mandate a specific EDMS but requires that the system used provides a clear audit trail of submissions, reviews and approvals.

For contractors and project teams, the practical implication of these changes is that the shop drawing approval process can now be managed entirely electronically under AISC 303-22. This should reduce the time and cost of the shop drawing process compared to paper-based workflows. However, the electronic process must still meet the substantive requirements of AISC 303-22 – the approval must be traceable, the approver must be identified and the date of approval must be recorded.

2. Building Information Modelling (BIM) Provisions (Section 4)

AISC 303-22 includes new provisions addressing the use of Building Information Modelling (BIM) in structural steel construction. The 2016 edition did not address BIM. The 2022 edition recognises that BIM is now widely used on structural steel projects and defines the responsibilities of the fabricator and the erector in relation to BIM models.

Key BIM provisions in AISC 303-22 include:

Fabricator’s BIM model – the fabricator’s 3D model (typically produced in Tekla Structures or a similar detailing software) is the basis for the shop drawings. AISC 303-22 clarifies that the fabricator’s model is a shop drawing for the purposes of the standard and is subject to the same submission and approval requirements as traditional shop drawings.
Model coordination – AISC 303-22 defines the responsibilities of the fabricator and the erector in relation to the coordination of the structural steel model with other discipline models (architectural, mechanical, electrical, plumbing). The standard requires that the scope of model coordination be defined in the contract documents. If the contract documents do not define the scope of model coordination, the default provisions of AISC 303-22 apply.
Model ownership and use – the 2022 edition addresses the ownership of the fabricator’s BIM model and the permitted uses of the model by the owner and other parties. The fabricator retains ownership of the model. The owner may use the model for the purposes defined in the contract documents but may not use it for purposes beyond those defined without the fabricator’s consent.
Clash detection – AISC 303-22 clarifies the responsibilities for clash detection between the structural steel model and other discipline models. The standard does not require the fabricator to perform clash detection with other disciplines unless this is specifically required by the contract documents.

For contractors and project teams, the BIM provisions of AISC 303-22 are significant because they define the default scope of the fabricator’s BIM obligations. If the project requires BIM coordination beyond the default provisions – for example, full federated model coordination with all disciplines – this must be specified in the contract documents and priced accordingly. Assuming that the fabricator will perform extensive BIM coordination without specifying it in the contract is a common source of disputes on BIM-enabled projects.

3. Revised Design Drawing Requirements (Section 3)

Section 3 of AISC 303-22 has been revised to update the minimum information requirements for design drawings. The 2022 edition clarifies what the engineer of record must show on the design drawings to enable the fabricator to produce shop drawings without requesting additional information.

Key changes in Section 3 include:

Connection design responsibility – AISC 303-22 clarifies the division of responsibility for connection design between the EOR and the fabricator. The EOR is responsible for the design of all connections shown on the design drawings. Where the EOR delegates connection design to the fabricator (a common practice for standard shear connections), the design drawings must clearly identify which connections are delegated and what the design criteria are (loads, geometry, material grades).
Camber requirements – the 2022 edition clarifies the requirements for specifying camber on design drawings. The EOR must specify the required camber for each beam that requires cambering. The fabricator is responsible for achieving the specified camber within the tolerances defined in Section 6.
Surface treatment requirements – the 2022 edition requires that the design drawings clearly specify the surface treatment requirements for all structural steel, including the surface preparation standard, the coating system and the areas to be left uncoated (for example, faying surfaces of slip-critical connections and areas to be field welded).

4. Fabrication Tolerances (Section 6)

The fabrication tolerances in Section 6 of AISC 303-22 have been revised and clarified in several areas. The key changes are:

HSS fabrication tolerances – the 2022 edition includes revised fabrication tolerances for hollow structural sections (HSS) that reflect the tighter dimensional tolerances of A1085 HSS compared to A500 HSS. The revised tolerances are more consistent with the actual dimensional accuracy achievable with A1085 material.
Camber tolerances – the camber tolerances in Section 6 have been revised to provide clearer guidance on the acceptable range of camber for beams of different lengths and weights. The revised tolerances reflect current fabrication practice and the capabilities of modern cambering equipment.
Straightness tolerances – the straightness tolerances for columns and other compression members have been clarified to be consistent with the stability analysis requirements of AISC 360-22 Chapter C.

5. Erection Tolerances (Section 7)

The erection tolerances in Section 7 of AISC 303-22 are unchanged from the 2016 edition. The key erection tolerances remain:

Element	Tolerance (303-16)	Tolerance (303-22)	Change
Column plumbness (multi-storey)	1/500 of height, max 1 in. in first 20 stories	1/500 of height, max 1 in. in first 20 stories	No change
Column base elevation	±1/8 in.	±1/8 in.	No change
Column plan position	±1 in. at base	±1 in. at base	No change
Beam elevation at ends	±3/8 in.	±3/8 in.	No change
Beam sweep	3/8 in. ≤30 ft; 1/2 in. >30 ft	3/8 in. ≤30 ft; 1/2 in. >30 ft	No change

The unchanged erection tolerances reflect the fact that the physical capabilities of steel erection have not changed significantly since the 2016 edition. The tolerances represent the practical limits of what can be achieved with current equipment and methods. Tightening the tolerances without a corresponding change in erection technology would simply result in more out-of-tolerance work and more costly corrections.

6. Architecturally Exposed Structural Steel (AESS) – Section 10

Section 10 of AISC 303-22, which covers Architecturally Exposed Structural Steel (AESS), has been revised and expanded. AESS is structural steel that is visible in the completed building and is subject to additional fabrication and erection quality requirements beyond those for standard structural steel.

Key changes in Section 10 include:

Revised AESS categories – the 2022 edition retains the AESS category system from the 2016 edition (AESS 1 through AESS 4, plus AESS C for custom requirements) but provides more detailed guidance on the requirements for each category. The categories range from AESS 1 (standard structural steel with basic surface preparation) to AESS 4 (the highest level of finish, with all welds ground smooth, all surfaces prepared to a high standard and tight dimensional tolerances).
Mock-up requirements – the 2022 edition clarifies the requirements for AESS mock-ups. For AESS 3 and AESS 4 work, a mock-up panel must be fabricated and approved by the owner before production fabrication starts. The mock-up defines the acceptable standard of finish for the production work.
Handling and protection – the 2022 edition includes more detailed requirements for the handling and protection of AESS during fabrication, transport and erection. AESS is more susceptible to damage than standard structural steel and requires more careful handling to maintain the required surface finish.

For contractors and project teams, the AESS provisions of AISC 303-22 are important because AESS work is significantly more expensive than standard structural steel work. The additional cost of AESS – more careful fabrication, more extensive surface preparation, mock-up requirements, more careful handling and erection – must be identified at bid stage and included in the estimate. A bid that prices AESS at standard structural steel rates will lose money.

7. Errors and Omissions (Section 9)

Section 9 of AISC 303-22, which covers contracts and the handling of errors and omissions, has been revised to provide clearer guidance on the procedures for identifying and resolving errors and omissions in the design documents.

Key changes in Section 9 include:

Fabricator’s obligation to identify errors – the 2022 edition clarifies that the fabricator has an obligation to notify the EOR of errors and omissions in the design documents that are identified during the shop drawing process. The fabricator is not responsible for errors in the design documents but must not proceed with fabrication of work that is known to be in error without notifying the EOR.
EOR’s obligation to respond – the 2022 edition clarifies that the EOR has an obligation to respond to the fabricator’s notifications of errors and omissions in a timely manner. Delays in responding to error notifications that cause fabrication delays are the owner’s risk, not the fabricator’s.
Cost of corrections – the 2022 edition clarifies the allocation of the cost of correcting errors and omissions. Errors in the design documents that require changes to fabricated or erected steel are the owner’s cost. Errors in the shop drawings that require changes to fabricated or erected steel are the fabricator’s cost.

What Did Not Change from AISC 303-16 to AISC 303-22

While the 2022 edition includes significant changes, many of the core provisions of AISC 303 are unchanged from the 2016 edition. The following key provisions remain the same:

Erection tolerances – unchanged as described above
Shop drawing approval process – the substantive requirements for shop drawing submission, review and approval are unchanged. The EOR must review and approve shop drawings before fabrication starts. The EOR’s review is for general conformance with the design intent – it does not relieve the fabricator of responsibility for the accuracy of the shop drawings.
Mill certification requirements – the requirements for mill certifications are unchanged. MTRs must be obtained for all structural steel materials and retained by the fabricator.
Division of responsibility – the fundamental division of responsibility between the owner, the EOR, the fabricator and the erector is unchanged. The EOR is responsible for the design. The fabricator is responsible for the accuracy of the shop drawings and the quality of the fabrication. The erector is responsible for the stability of the structure during erection and the quality of the erection.
Column anchorage – the requirements for column anchorage – minimum four anchor rods per column, the erector’s responsibility to verify that anchor rods are set correctly before erection starts – are unchanged.
AISC Certification – the references to AISC Certification as a means of demonstrating compliance with the QC requirements are unchanged.

Practical Implications for Contractors and Project Teams

The changes from AISC 303-16 to AISC 303-22 have several practical implications for contractors, fabricators and erectors working on projects designed to ANSI/AISC 360-22.

Shop Drawing Process

The formal recognition of electronic submission and approval in AISC 303-22 should streamline the shop drawing process on projects that use electronic document management systems. Contractors and project teams should confirm at the pre-construction meeting that the electronic approval process meets the requirements of AISC 303-22 – traceable, identified approver, recorded date of approval.

BIM Coordination Scope

The new BIM provisions in AISC 303-22 make it essential to define the scope of BIM coordination in the contract documents. If the project requires BIM coordination beyond the default provisions of AISC 303-22, this must be specified and priced. Contractors should review the BIM requirements in the contract documents carefully and confirm the scope of the fabricator’s BIM obligations before award.

AESS Identification and Pricing

The revised AESS provisions in AISC 303-22 make it more important than ever to identify AESS work at bid stage and price it correctly. AESS work is significantly more expensive than standard structural steel work. The AESS category must be identified on the design drawings. If the design drawings do not clearly identify the AESS category, the contractor should request clarification before bidding.

Connection Design Responsibility

The revised Section 3 provisions clarifying connection design responsibility make it important to confirm at bid stage which connections are delegated to the fabricator and what the design criteria are. If the design drawings do not clearly identify delegated connections and their design criteria, the contractor should request clarification before bidding. Ambiguity about connection design responsibility is a common source of disputes on structural steel projects.

HSS Material

The revised fabrication tolerances for HSS in AISC 303-22 reflect the tighter dimensional tolerances of A1085 HSS. Fabricators should confirm with their steel supplier whether A1085 is available for the required sizes and whether there is a price premium over A500 Grade C. The revised tolerances should be reviewed when pricing HSS fabrication to confirm that they are achievable with the proposed material and fabrication process.

AISC 303-22 and the Efficient Construction Cost (ECC)

AISC 303-22 affects the Efficient Construction Cost (ECC) through its requirements for the shop drawing process, BIM coordination, AESS fabrication and erection, and the handling of errors and omissions. The key cost implications are:

BIM coordination – if the contract requires BIM coordination beyond the default provisions of AISC 303-22, the additional cost must be included in the ECC. BIM coordination is not free – it requires dedicated BIM staff, software licences and coordination time.
AESS fabrication and erection – AESS work is significantly more expensive than standard structural steel work. The additional cost of AESS must be identified at bid stage and included in the ECC. Typical AESS cost premiums range from 20% for AESS 1 to 100% or more for AESS 4.
Electronic document management – the cost of implementing and maintaining an electronic document management system that meets the requirements of AISC 303-22 must be included in the project overhead.
Errors and omissions – the revised Section 9 provisions clarify that the cost of correcting errors in the design documents is the owner’s risk. Contractors should ensure that their contracts reflect this allocation of risk and that they have a process for identifying and notifying the EOR of errors and omissions in a timely manner.

Summary

AISC 303-22 is the current edition of the Code of Standard Practice for structural steel construction in the USA. The key changes from the 2016 edition are the formal recognition of digital delivery and electronic processes, the new BIM provisions, the revised design drawing requirements, the revised AESS provisions and the clarified errors and omissions procedures. The erection tolerances and the fundamental division of responsibility between the parties are unchanged. The key principles for contractors and project teams are:

Confirm that the project is governed by AISC 303-22 – not the 2016 edition
Ensure that the electronic shop drawing approval process meets the requirements of AISC 303-22
Define the scope of BIM coordination in the contract documents – do not rely on the default provisions if the project requires more extensive coordination
Identify AESS work at bid stage and price it correctly using the AISC 303-22 category system
Confirm connection design responsibility at bid stage – identify which connections are delegated to the fabricator and what the design criteria are
Implement a process for identifying and notifying the EOR of errors and omissions in the design documents
Include the cost of AISC 303-22 compliance – BIM coordination, AESS, electronic document management – in the ECC

A project team that understands AISC 303-22 and builds its requirements into the methodology, the programme and the estimate will manage the structural steel package efficiently and avoid the disputes that arise from ambiguity about responsibilities, scope and process. One that does not will discover the cost of that ambiguity on site – where it is always more expensive to resolve than it would have been if it had been addressed at bid stage.

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