Commissioning drawing review

Why does commissioning review drawings?

Commissioning is the systematic process of ensuring building systems perform as intended. The commissioning agent (CxA) reviews drawings at multiple design stages to catch issues that would otherwise surface only during functional testing, when fixes are expensive and schedule-critical. A good CxA review at DD or 60% CD prevents the most common categories of late-stage rework.

What commissioning review milestones matter?

Commissioning drawing review starts with the Owner's Project Requirements and Basis of Design, then checks drawings at each design milestone before functional testing.

• Owner's Project Requirements (OPR) review, confirms design intent is documented before drawings exist
• Basis of Design (BOD) review, confirms designer's response to OPR
• Schematic Design (SD) review, verifies system selection aligns with OPR
• Design Development (DD) review, verifies sizing, zoning, and controls strategies
• 60% / 95% Construction Documents review, detail-level coordination, sequence of operations, and testability
• Submittal review, verifies submitted equipment matches design and OPR

What should commissioning look for in mechanical drawings?

On mechanical drawings, confirm equipment schedules match the BOD, zoning matches occupancy, and outdoor-air calculations meet ASHRAE 62.1.

• Equipment schedules match the BOD and OPR sizing
• System zoning aligns with intended occupancy and use patterns
• Outdoor air calculations meet ASHRAE 62.1 and any project enhancement targets
• Sequence of operations included for every system, not just summarized
• Control sensor locations specified and accessible for verification
• Test ports, balancing dampers, and measurement stations shown
• Equipment access for maintenance and testing reachable per code
• Heat recovery, economizer, and DCV controls clearly specified
• Hydronic system arrangement supports proper balancing

What should commissioning look for in electrical drawings?

On electrical drawings, confirm panel schedules show actual loads, emergency transfer schemes are testable, and lighting controls include daylight and occupancy.

• Panel schedules show actual loads and demand factors
• Emergency and standby power transfer schemes clear and testable
• Lighting controls include daylight, occupancy, and time-of-day per IECC
• Sub-metering points specified per OPR or jurisdiction requirements
• Power quality measurement (where required) accessible for monitoring
• Equipment locations match mechanical drawings (no orphan power feeds)

What should commissioning look for in plumbing and fire protection?

On plumbing and fire-protection drawings, confirm hot-water recirculation is balanced, backflow preventers are accessible, and the fire-pump test header is documented.

• Domestic hot water recirculation balanced and metered
• Backflow preventers accessible for annual testing
• Fire pump test header location and discharge path documented
• Sprinkler hydraulic calculations match the system delivered
• Standpipe test connection accessible

Why should you not skip the sequence of operations?

The single biggest source of late-stage commissioning rework is missing or vague sequences of operations. A good CxA review confirms that every controlled system has a written sequence that covers occupied mode, unoccupied mode, warm-up, cool-down, alarms, safeties, and failure modes. If the sequence is described only as "system shall maintain comfort conditions," that's a flag.

Which documents are required for functional testing?

Functional testing needs the approved sequence of operations, installed-equipment submittals, the Test and Balance report, and the control-system points list.

• Final approved sequence of operations
• Submittal data for installed equipment
• Approved Test & Balance report
• Control system points list and graphics
• Updated drawings reflecting field changes
• Manufacturer startup reports
• Equipment trend data covering minimum required test period