What Architectural Drawings Show That Structural Drawings Don't
Structural drawings define member sizes, connection loads, and framing layout. Architectural drawings define what has to fit around the steel — ceiling heights, mechanical chases, cladding attachment points, facade systems, and partition walls that land on steel beams. Copes, haunch cuts, and clip clearances often cannot be determined from structural drawings alone.
- Soffit and ceiling elevations that drive beam cope depths
- Curtain wall and facade attachment details that attach to structural steel
- Stair and elevator shaft framing that connects to structural members
- Mechanical room clearances that affect beam cope and stub locations
- Embed and anchor point locations for non-structural attachments
The Cost of Missing Architectural Information
When architectural drawings are absent during detailing, the detailer assumes worst-case clearances or leaves items for field resolution. Both options cost money. Field copes and field-drilled holes are expensive and slow erection. Changes discovered after fabrication — when members are already cut and drilled — require new material, scrap the old, and delay the erection sequence.
What to Do When Architectural Drawings Are Not Ready
If architectural drawings are genuinely not available at detailing kickoff, the best practice is to start with structural primary members and hold miscellaneous steel, cladding connections, and architectural attachments as a separate release. Document the assumption clearly in the detailing proposal so the fabricator knows which items are held. When architectural drawings are issued, those held items can be detailed and released as a separate package without disrupting the primary framing.
Facade and Cladding Attachment Coordination
Modern building envelopes — curtain wall, metal panel, precast — attach to the structural frame through embed plates, weld plates, and cast-in clips. The embed locations, sizes, and edge distances are defined on the architectural and facade contractor's drawings, not on the structural set. If the detailer works only from structural drawings, embeds are missed entirely or placed incorrectly. The architectural drawings also govern the top-of-steel elevation adjustments required when a finished floor or ceiling height changes — a revision that appears as a minor note on the architectural plan but requires re-modeling every column and beam in that zone.
- Curtain wall embed plates — locations and edge distances shown only on facade drawings
- Precast bearing connections — bearing plate sizes and ledge geometry from architectural/precast shop drawings
- Hollow metal door frames — anchor bolt and embed requirements at steel columns near door openings
- Stair and guardrail anchorages — post base and rail embed locations frequently omitted from structural drawings
Mechanical and Electrical Coordination Through the Architectural Set
Architectural reflected ceiling plans (RCPs) are the most useful drawings for determining clearance requirements at beam soffits. When a corridor ceiling is at 9'-0" AFF and a wide-flange beam runs parallel to that corridor at 9'-4" AFF, the beam depth may require the ceiling to break or the beam to shift — and the structural drawings alone will not show this conflict. Architectural sections through mechanical rooms, shaft spaces, and low-clearance areas are equally critical for identifying cope conditions and beam orientation requirements. Detailing from structural drawings alone in a complex building without this coordination is detailing with half the information.
How to Stage Detailing When Architectural Information Is Partial
When architectural drawings are partially complete at detailing kickoff, the best practice is to stage the scope: (1) release primary structural framing using the structural drawings and the available architectural information; (2) identify specific items that require architectural confirmation and flag them as held items in the model using Tekla's phase attribute; (3) issue a written held-item log to the fabricator and PM listing every held item, the reason it is held, and the information required to release it; (4) release held items as the information arrives. This approach is significantly more efficient than remodeling items after the fact.
- Phase 1: Primary framing — columns, girders, primary beams — released on structural drawings only
- Phase 2: Secondary framing at clearance-critical locations — held until architectural clearance confirmed
- Phase 3: Miscellaneous steel and cladding attachments — released when architectural and facade drawings are complete
- Held-item log issued weekly to PM until all held items are released
Stair and Guardrail Framing — An Often-Overlooked Coordination Point
Stair framing and guardrail anchorages are among the most common items delayed by missing architectural information. The stair layout — rise, run, landing elevations, and guardrail post spacing — is defined exclusively on the architectural drawings. The structural drawings typically show only the primary landing beams and stringer support points. Without the architectural stair drawings, the detailer cannot set stringer end conditions, landing plate dimensions, or guardrail post base embed locations. When architectural stair drawings arrive after primary structural detailing is complete, the stair framing must be modeled as a separate scope item — adding time and cost that could have been avoided. On projects with steel pan stairs, guardrails, or ornamental railings, confirm these architectural drawings are in the package before detailing kickoff. Reference AISC Design Guide 17 for guidance on stair and railing connection geometry and OSHA 1926.502 for guardrail height and load requirements, both of which are governed by the architectural design, not the structural engineer's drawings.
Quality Control — Coordinating Architectural Drawings Against the Structural Model
The final quality check before any shop drawing submittal should include a visual overlay of the architectural floor plans against the Tekla structural model. In Tekla Structures, this can be accomplished by referencing DWG or DXF exports of architectural plans as reference objects, allowing the modeler to visually verify beam positions, column setbacks, and cope clearances against the architectural geometry. Navisworks provides a more rigorous coordination check by importing both the structural NWC file and the architectural Revit model and running automated clash rules. The AISC Code of Standard Practice Section 4.4 requires the detailer to coordinate with other trades and disciplines to the extent of the information provided — which means the responsibility for coordination gaps caused by missing architectural information rests with the party who withheld it. Documenting what was checked, what was missing, and when the missing information was requested protects the detailer and the fabricator if architectural coordination issues surface in the field.
- Reference architectural DWG/DXF files in Tekla as model reference objects for visual cope and clearance checks
- Run structural-to-architectural clash rules in Navisworks before submittal
- Document all held items with the specific architectural drawing needed
- Issue written RFIs when architectural information is needed and missing
- Confirm top-of-steel elevations against finished floor elevations on architectural plans