Every building is a puzzle of overlapping systems. Structural beams, ductwork, plumbing risers, electrical conduits, fire protection piping, and technology infrastructure all compete for the same physical space. Coordination drawings exist to solve that puzzle before construction starts.

A coordination drawing overlays multiple discipline drawings onto a single view so the project team can identify spatial conflicts between systems that would otherwise be designed in isolation. Composite plans take this further by combining all systems at a specific floor level into one drawing, showing exactly where ducts cross beams or pipes collide with conduit runs. Combined service drawings consolidate related utility systems, like mechanical, electrical, and plumbing, into unified service corridor plans that reveal the vertical stacking of systems within ceiling plenums and chases.

For the PjM exam, you need to evaluate when and how these drawings should be produced, who bears responsibility for design coordination versus construction coordination, and what happens when coordination breaks down. The distinction between the architect's coordination role and the contractor's coordination role is a frequent source of claims and disputes on BIM-enabled projects. Getting this wrong on a project means field conflicts, costly change orders, and schedule delays. Getting it wrong on the exam means missed points.

This topic connects directly to quality control, constructability review, and BIM execution planning.