What Scope Definition Covers
A complete detailing scope definition answers six questions: What steel is included? What drawings will be produced? Who designs the connections? What software platform will be used? What non-drawing deliverables are required? And what constitutes a change order? Each question left unanswered becomes a future dispute.
- Structural steel vs. miscellaneous steel — each may be a separate scope item
- Drawing types — shop, erection, approval, anchor bolt, embed, single-part
- Connection design responsibility — EOR-designed, delegated to fabricator, or detailer-designed with PE stamp
- Non-drawing deliverables — BOM, CNC files, IFC model, bolt list, paint-area reports
- Change order triggers — design changes, addenda revisions, additional drawing types
Connection Design Is the Most Critical Scope Item
Detailing proposals that do not explicitly define connection design responsibility are priced with an assumed scope. If the EOR later assigns connection design to the fabricator — and the detailer was not priced for it — the result is either an uncompensated scope addition or a change order. State this explicitly in the contract: 'Connection design by EOR shown on structural drawings' or 'Connection design delegated to fabricator; detailer to prepare calculations under separate PE engagement.'
Documenting Scope to Prevent Change Orders
Write scope exclusions as clearly as inclusions. Common explicit exclusions: miscellaneous steel not shown on structural drawings, connection design for connections where loads are not provided, drawings for items stamped 'by others,' revisions resulting from design changes after IFC issuance, and BIM coordination beyond the structural model. Every exclusion that a fabricator agrees to at contract time is a dispute that never happens.
Software and Deliverable Scope
The detailing software platform is a scope item — not an assumption. If the fabricator's CNC equipment requires DSTV NC1 files from Tekla Structures version 2023 or later, that must be in the scope. If the GC requires IFC 4 deliverables for BIM coordination, that is a scope item with a specific format requirement. If erection drawings are required in addition to shop drawings, that is a scope item. Each deliverable type adds production time, and a firm that was priced for shop drawings only and then asked to produce erection drawings and a coordinated IFC model has grounds for a change order.
- Detailing software platform and version — Tekla 2023, SDS/2 18.0, etc.
- CNC file format — DSTV NC1, DXF, machine-proprietary format
- IFC version and LOD — IFC 2x3, IFC 4, LOD 300, LOD 350
- Drawing types — shop drawings, erection drawings, anchor bolt plans, single-part drawings, assembly drawings
- BIM coordination participation — model submission schedule, meeting attendance, clash response time
Change Order Triggers — Write Them Before They Matter
A well-written scope of work includes an explicit list of change order triggers — conditions that will generate a change-order notice regardless of whether either party expected them. Standard triggers: addenda issued after IFC that require model changes; design changes directed by the EOR after the model is 50% complete; connection type changes that affect more than 10% of the member count; additional drawing types not listed in the original scope; BIM coordination scope beyond the structural model. Writing these triggers before the project starts means neither party is surprised when one occurs.
Revision Allowances — Scope Within the Scope
Most detailing engagements include a revision allowance — a defined number of revision rounds or revision hours included in the base fee. This allowance covers the normal EOR review cycle and minor design refinements. It does not cover major design changes, addenda-driven model rebuilds, or erection-sequence revisions. State the revision allowance explicitly: 'Base fee includes two rounds of EOR review comments per drawing and up to 15% of the original member count in design-change revisions. Additional revision work is billed at $[rate] per hour.' Without this language, the detailer has no basis for additional fees when revision work exceeds the estimated scope.
Miscellaneous Steel — The Scope Item Most Likely to Grow
Miscellaneous steel is the most frequent source of scope creep in structural steel detailing. Structural drawings typically define primary and secondary framing with reasonable completeness, but miscellaneous items — steel stairs, ladders, catwalks, equipment supports, embed plates, roof hatch frames, pipe penetration sleeves, mechanical equipment platforms — are often shown on only some of the project documents, or referenced across architectural, structural, and MEP drawings without appearing completely on any single set. A detailing scope that says 'miscellaneous steel included' without a defined list has no boundary. The scope should either enumerate the miscellaneous steel items explicitly — using the structural drawing index as a reference — or state that miscellaneous steel is excluded and is to be priced separately when issued. AISC Code of Standard Practice Section 2.2 defines the fabricator's scope as work shown on structural design drawings, which is useful contract language when enforcing a scope boundary against items that appear only on architectural drawings.
- Steel stairs and platforms — include only if shown on structural drawings or specifically listed
- Embed plates and weld plates — confirm whether located on structural or architectural drawings
- Equipment support frames — typically defined on MEP drawings; confirm inclusion in writing
- Roof hatch frames and curb angles — often referenced on architectural roofing drawings only
- Pipe penetration reinforcing — framing around MEP penetrations that is frequently undefined at kickoff
BIM and Coordination Scope — Where Detailing Ends and BIM Begins
BIM coordination is a scope item that is frequently assumed rather than explicitly defined. The detailing scope should state clearly: whether the detailer will produce an IFC model for multi-discipline coordination; which IFC version (2x3 or IFC 4) and LOD (200, 300, 350) are required; how frequently model updates will be issued to the GC's BIM coordinator; whether the detailer will attend coordination meetings; and how long after fabrication release the model will be maintained and updated. Each of these items has a production cost. A detailing firm that prices for producing shop drawings only and is then expected to attend weekly BIM coordination meetings, respond to clash reports within 24 hours, and maintain the model through construction closeout has grounds for a substantial change order. The BIM Execution Plan (BEP) — if one exists — should be attached to the detailing scope document and its requirements explicitly accepted or excluded in the contract. For complex projects with Navisworks-based coordination and LOD 350 model requirements, the BIM coordination scope can represent 15–25% of the total detailing effort.