Most Coordination Errors Are Found - and Fixed - During the CD Phase
A construction project involves drawings and specifications from multiple disciplines: architecture, structural engineering, mechanical (HVAC), plumbing, electrical, fire protection, civil, and often others. For the building to work as designed, all these documents must be consistent with each other. The cost of finding and fixing a coordination error in the drawing set is a fraction of the cost of discovering it during construction. The ARE PDD tests coordination skills because producing coordinated construction documents is one of the most important and most difficult things an architect does in practice.
What to Coordinate with Structural
- Column grid alignment: Architectural and structural drawings must use the same column grid, with matching dimensions and column designations.
- Slab openings: Every floor penetration for stairs, elevators, mechanical shafts, and large pipes must appear on both architectural and structural drawings consistently.
- Bearing wall locations: Load-bearing walls must be consistently shown on both sets and must align with the structural layout.
- Beam depths: Structural beam depths affect floor-to-floor heights. If the structural engineer specifies a 24" beam where the architect showed 18", the ceiling height changes.
- Foundation walls: Architectural basement walls must match structural foundation wall locations and thicknesses.
What to Coordinate with Mechanical/HVAC
- Shaft locations: HVAC duct shafts must appear on architectural floor plans, coordinated with structural framing and program areas.
- Mechanical room sizes: Mechanical rooms must be large enough to accommodate equipment (AHUs, boilers, chillers) and provide the required service clearances.
- Ceiling heights: HVAC ductwork and equipment in ceiling plenum must fit within the available plenum depth without encroaching on the finished ceiling height.
- Roof penetrations: Rooftop equipment curbs, exhaust fans, and duct penetrations must be shown consistently on architectural roof plans and mechanical drawings.
What to Coordinate with Electrical
- Panel room and transformer vault sizes and locations.
- Ceiling-mounted devices: Light fixtures, emergency lighting, fire alarm devices, and security cameras must be coordinated in the ceiling plane to avoid conflicts with structure and mechanical equipment.
- Electrical rooms: Must be accessible and sized to code.
Coordination Tools and Process
- Overlay review: Printing architectural, structural, and MEP drawings at the same scale and overlaying them (physically or digitally) to look for conflicts.
- BIM clash detection: Using a federated model to automatically find conflicts before documents are issued.
- Coordination meetings: Regular drawing coordination meetings with all discipline leads during the CD phase, working through a coordination checklist.
- Discipline review requests (DRRs): Formal requests for each consultant to review a portion of the architectural drawings for conflicts.
Key Exam Points
- Coordination errors are cheaper to fix on paper than in the field - CD coordination is critical.
- Structural: grids, slab openings, bearing walls, beam depths must match architecture.
- HVAC: shafts, mechanical rooms, ceiling heights, roof penetrations need to align with architectural drawings.
- Electrical: panel rooms, ceiling device coordination, electrical room sizing.
- BIM clash detection and drawing overlays are primary coordination tools.
Study PDD on AREprep
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