The Detailer's Responsibility
A professional detailing firm is expected to review the project documents before kickoff and flag obvious gaps: missing addenda, unresolved connection design responsibility, missing geotechnical information for base plates, and MEP drawings absent when BIM coordination is required. At Tectonix, every project receives a documented scope review within 48 hours of kickoff — identifying what is missing, what assumptions are being made, and what decisions are needed from the fabricator before modeling begins.
The Fabricator's Responsibility
The fabricator knows the project context in ways the detailer does not: the general contract scope, verbal agreements with the GC, shop-specific capabilities, and which items were included in the fabrication bid. Fabricators should communicate these to the detailer at kickoff rather than expecting the detailer to discover them through the drawings. Items that were in the fabrication bid but not shown on structural drawings are exactly the items that slip through scope gaps.
What Happens When Gaps Are Found During Detailing
When scope gaps are discovered after modeling has started, they should be documented immediately in writing — as an RFI if the gap is engineering-related, or as a change-order notice if the gap is a scope addition. Informally absorbing scope gaps 'to keep the project moving' creates precedent for absorbing future additions and ultimately leads to a detailing team that is working unpaid.
The EOR's Role in Scope Gap Identification
The engineer of record is not typically involved in detailing scope definition — but EOR-issued documents often contain gaps that become detailing scope gaps. An EOR who shows a column on the structural plans but has no design for the column base plate has created a scope gap: the detailer cannot detail a base plate that has not been designed. When these gaps appear, the detailer's obligation is to surface them as RFIs to the EOR, not to design the missing element. EORs who respond promptly to these RFIs with completed designs allow detailing to proceed; EORs who are slow create the most predictable schedule delay in the fabrication workflow.
Common Scope Gap Categories in Steel Detailing
Understanding which scope items are most frequently undefined helps all parties check for them at project start rather than discover them mid-project.
- Miscellaneous steel scope: is misc steel in scope, and is every category of misc steel defined — stairs, handrails, ladders, embeds, grating frames, platforms?
- Connection design: is the 'design by fabricator' notation comprehensive or partial — what happens to connections where loads are not shown?
- Seismic SFRS elements: are all special moment frame or braced frame elements identified and are AISC 341 requirements explicitly acknowledged?
- Non-structural steel: cladding supports, parapet frames, equipment supports — who details these, and are they included?
- Existing structure connections in renovations: connections to existing steel require field verification that is not always in scope
- Phased release coordination: is the detailer responsible for coordinating release schedules with the shop, or does the fabricator manage this internally?
The Pre-Kickoff Scope Gap Review
The most effective scope gap identification happens before kickoff — in a structured document review that the detailer conducts against the submitted project package. This review should produce a written gap list delivered to the fabricator within 48 hours of receiving documents. The list should identify: every document missing from the package, every undefined design responsibility, every item on the drawings where the detailer cannot proceed without additional information. This document is not a complaint — it is a professional service that protects the fabricator from change orders and the detailer from out-of-scope work that erodes the project margin.
How Scope Gaps Create Change Orders
Scope gaps discovered during detailing become change orders — period. The question is not whether they will generate additional cost, but whether that cost is identified early (when it is small and manageable) or late (when rework, schedule compression, and disruption multiply the cost). A scope gap that requires three additional drawings and adds two weeks to the schedule costs far more in disruption than the drawing fee alone. Identifying gaps before modeling starts is worth more than any other investment of PM time at project inception.
Creating a Scope Gap Checklist for Your Next Project
Fabricators and detailing PMs who have been through scope gap disputes on previous projects develop a personal checklist of items to verify at every project kickoff. A structured checklist removes the reliance on memory and ensures that the same questions get asked on every project — regardless of project size, project type, or which team members are involved. A practical scope gap checklist for steel detailing should address the following categories: document completeness (is every discipline present, at the right revision, and have all addenda been incorporated?); connection design responsibility (is every connection accounted for — standard framing, seismic SFRS connections, column base plates, embeds, and moment connections at transfer structures?); miscellaneous steel scope (which categories are included, and is there a complete list or is the scope open-ended?); BIM and coordination scope (what model deliverables are required, at what LOD, and when?); and change order triggers (are they listed in the proposal, and has the fabricator acknowledged them?). Running through this checklist takes under 30 minutes at kickoff and has a documented history of preventing disputes worth multiples of that time investment.
- Document completeness: structural, architectural, MEP, specifications, addenda all accounted for
- Connection design: every connection type assigned to a responsible party with a clear design basis
- Miscellaneous steel: enumerated list of included items, not an open-ended 'as shown' reference
- BIM/IFC: version, LOD, frequency of updates, and meeting attendance obligation confirmed
- Revision allowance: number of cycles included, rate for additional cycles, stated in writing
- Change order triggers: listed in proposal and acknowledged by fabricator before award