Design Review and Pre-Construction Commissioning Activities
Design review by the CxA is a focused, iterative check that the design is commissionable and consistent with the OPR. It is not a substitute for the architect's or engineer's professional review; the CxA looks for clarity, completeness, testability, and maintainability. Reviews typically occur at schematic design, design development, and construction documents, each producing a written report with issues ranked by impact.
Key review targets: sequences of operation (are they complete and unambiguous?), control diagrams, equipment accessibility and service clearances, sensor and test-port locations, balancing valves and dampers, isolation and bypass provisions, and provisions for safe functional testing. A design that cannot be safely or practically tested is a commissioning risk.
Common traps: (1) assuming the CxA approves design - the CxA comments and recommends; the design professional retains responsibility; (2) skipping review of controls sequences, which is where most functional failures originate; (3) failing to verify that design documents include commissioning scope and requirements in the specifications. Pre-construction activities also include finalizing the Commissioning Plan, developing the issues log, reviewing contractor submittals relevant to commissioned systems, and confirming the construction schedule supports testing windows.
Rule of thumb: review sequences of operation line by line against the OPR - most operational deficiencies trace back to incomplete or contradictory sequences. Worked example: a review finds a chiller plant sequence that never defines lead/lag rotation timing. The CxA logs it, the designer adds a defined rotation interval, and the functional test later verifies the rotation occurs as specified.