Fundamentals of Building Commissioning
Commissioning (Cx) is a quality-focused, documented process applied from pre-design through occupancy to verify that building systems perform in accordance with the owner's project requirements (OPR) and the basis of design (BOD). Understand the cast: the owner sets the OPR; the commissioning authority (CxA) leads and documents the process and must be independent of the design and construction team to preserve objectivity; the contractor installs and self-tests; the design team produces the BOD. Distinguish new-building Cx from retro-commissioning (existing buildings, no design phase) and ongoing commissioning (continuous monitoring and trending).
Know the typical sequence: OPR, Cx plan, design review, submittal review, pre-functional checklists, functional performance tests (FPT), issues log resolution, systems manual, training, and a warranty-phase review. Traps in questions include confusing the CxA with the contractor's testing agent, assuming the CxA designs corrections (the CxA verifies and documents; others correct), and treating Cx as only a final walkthrough. Another trap: the OPR is the owner's document, not the designer's.
Rule of thumb: if a proposed activity does not trace back to a documented requirement in the OPR, question why it is in scope. Worked example: a school district wants to confirm a new chiller plant meets its efficiency and redundancy goals. The CxA first confirms the OPR states the goals, checks the BOD for how the design achieves them, then writes FPT procedures that measure capacity and verify lead/lag changeover, documenting results against those stated targets rather than generic manufacturer data.