Connection Design Assumptions
State clearly whether the proposal price assumes: connections are shown and designed by the EOR on the structural drawings; connections are delegated to the fabricator and the detailer will detail from EOR-provided loads; or connection design is included in the detailing scope under a separate PE engagement. The cost difference between these three scenarios can exceed 30% of the total detailing fee.
Drawing Count and Revision Allowances
Base drawing counts on the structural drawings provided at proposal time. If the project expands — more floors added, additional framing areas, revised connection types — those additions are change orders. State the included revision allowance explicitly: 'This proposal includes one revision cycle per drawing following EOR review comments. Additional revision cycles are priced at $X per drawing sheet.' Revision assumptions are the single most common source of post-project disputes.
Schedule, Software, and BIM Assumptions
Document the software platform (Tekla version), IFC version if required, EOR review turnaround assumption (typically 10 business days), and fabrication start date the schedule was built around. If the EOR takes 20 business days per review instead of 10, the detailing schedule extends and the team sits idle — that is not the detailer's cost.
- Software platform and version
- IFC version and LOD if BIM is required
- EOR review turnaround assumption
- Fabrication start date the schedule was planned around
- Number of approval submittal cycles included
Scope Boundary Assumptions
A proposal that does not define its scope boundary explicitly is a proposal without a price — because every undefined item is an assumption about inclusion or exclusion that the parties will discover they made differently. Common scope boundary assumptions that must be stated include: whether miscellaneous steel is in scope or excluded; whether MEP penetration reinforcing framing is included; whether connection calculations are to be prepared under a separate PE engagement or are excluded entirely; and whether the model will be maintained and updated through project closeout or handed off at fabrication release. Each of these represents hours of work that the detailer has either priced or not — and the fabricator deserves to know which.
Document Completeness Assumptions
Every proposal is priced against the documents received at proposal time. State what was received: 'This proposal is based on structural drawings dated [date], architectural drawings dated [date], and project specifications Division 05 dated [date]. Drawing and model revisions required by design changes issued after these dates are additional scope.' If the drawings received are preliminary or design-development rather than IFC-stamped, note that explicitly and state the assumption about how many revision cycles are expected when IFC drawings are issued. Fabricators who receive this clarity cannot later claim they did not know the drawings were incomplete.
Communication and Meeting Assumptions
Project management time is a real cost in detailing proposals, and it scales with the communication requirements of the project. State what is assumed: weekly progress calls included; one monthly coordination meeting included; additional BIM coordination meetings are priced at $X per meeting per hour. If the GC's BIM execution plan requires the detailing firm to attend weekly coordination meetings with all seven trades for six months, that is a significant commitment that must be priced. Proposals that assume standard communication requirements and receive high-demand projects create situations where the detailing PM is spending half their time in meetings and half their time managing the project — which is not what the fee was built to support.
Exclusions Are as Important as Inclusions
A well-written proposal section titled 'Exclusions' protects both parties. Common and important exclusions to state: structural engineering services and PE stamps unless specifically included; geotechnical engineering; concrete or rebar design; architectural detailing; MEP coordination beyond the structural model; commissioning; as-built verification surveys; and any scope not explicitly listed under inclusions. Exclusions that seem obvious to the detailer are often not obvious to the fabricator — particularly when the fabricator's GC contract includes items the fabricator assumed would come from the detailer. The exclusion list is the first document reviewed when a dispute arises over who should have provided something.