What Constitutes a Correction
A correction is a change to the detailer's work product to bring it into compliance with the documents that existed when the work was produced. If a hole pattern is wrong relative to the connection design shown on the structural drawings, that is a correction — the detailer made an error. If a weld symbol is missing that should have been included, that is a correction. Corrections are the detailer's responsibility and are included in the base fee.
What Constitutes a Scope Change
A scope change is a revision driven by a change in the design documents — an addendum, a design change, an EOR-initiated correction to their own drawings, or an owner directive. If the EOR adds a column to the framing plan after detailing has started, detailing that column is additional scope. If an addendum changes 40 beam connections from simple shear to moment, detailing those new connections is a change order. The test is simple: did the information that drives this change exist when the original scope was priced?
Documenting the Distinction
When a revision is received, document its source immediately: 'This revision is driven by EOR Addendum 3, dated [date].' Submit a change-order notice to the fabricator and GC before proceeding. If the revision is later disputed as a correction, the documented addendum reference is your evidence. Most disputes arise from revisions that were made without documentation — the detailer assumed it was a correction, the fabricator assumed it was a change order, and neither documented their assumption.
Grey Areas and How to Resolve Them
Not every revision falls cleanly into correction or scope change. The grey area arises when the original documents were ambiguous and the revision resolves the ambiguity. If the structural drawing showed a beam with no connection callout and the detailer assumed a standard shear tab, but the revision specifies a moment connection — was the shear tab assumption a correction or a scope change? The answer depends on how the original scope was written. If the scope said 'connections per structural drawings' and the structural drawing was silent, this is a scope change — the connection was not shown. If the scope said 'design connections per AISC standards' and the detailer used a non-compliant assumption, it may be a correction.
The Proactive Approach — Flag Ambiguities Before They Become Disputes
The most professional way to handle potential scope ambiguity is to flag it at the time it is encountered — not after the revision arrives. When a detailer encounters an undocumented condition during modeling, the right action is an RFI or a written assumption notice to the fabricator and PM: 'The structural drawings do not specify a connection at gridline B3-Level 2. We have assumed a standard shear tab per AISC Design Guide 9 Table 9-1. If the EOR requires a different connection type, this will be treated as a scope addition.' This notice sets the expectation before work proceeds and eliminates the surprise when a revision arrives.
- Log every assumption made during detailing with a date and basis
- Send assumption notices to the fabricator PM for any item not shown on structural drawings
- Reference the assumption in the RFI when a question arises about that item
- Treat EOR-directed changes to assumed conditions as scope changes, not corrections
- Require written sign-off from the fabricator PM on all assumption notices before proceeding
Contract Language That Protects Both Parties
The best protection against correction-versus-scope-change disputes is a well-drafted detailing contract that defines both terms explicitly. A robust contract clause should state: what constitutes the base design documents from which the detailer's scope is established (identified by drawing number and revision at time of contract); that changes to those base documents after a defined cutoff date are scope changes regardless of the reason for the change; and that the detailer's obligation to make corrections applies only to deviations from the base documents as-issued, not from subsequent revisions. Including this language in the original contract eliminates the need to reconstruct the document history when a dispute arises months later. The AISC Code of Standard Practice Section 4 provides an industry-recognized framework for defining contract documents that can be incorporated by reference.
Escalation Process When Classification Is Disputed
When a fabricator or GC disputes the detailer's classification of a revision as a scope change, the escalation path should follow the contract's dispute resolution procedure rather than devolving into informal argument. The first step is a written response from the detailer that cites the specific triggering document, its date, and the drawing or model content that existed before the triggering document was issued. The second step, if the dispute persists, is a meeting between the fabricator PM, the GC, and the detailing firm's principal. The third step is formal claim submission per the contract. Most classification disputes are resolved at step one when the document trail is produced. Disputes that reach step three typically involve genuinely ambiguous base documents, and those cases are settled by examining the original scope of work language against the pre-revision drawing set.