Commissioning Misses Due to Poor Spec/Print Review

Problem

During commissioning, you discover that input point X doesn't exist, feedback wiring is missing, or the equipment type specified doesn't match what's installed. Work halts until changes are made.

Root Cause

Specs and prints weren't reviewed for accuracy before work started. Controls designer assumed things would be correct but never verified.

Solution

1. Conduct Early Spec/Print Review (Before Design Finalized)

• Request mechanical/electrical drawings from design team
• Cross-reference controls specifications:
  • Do all specified devices actually exist in the mechanical design?
  • Are feedback points clearly marked on prints?
  • Is every control point actually accessible?
• Flag discrepancies immediately via RFI (Request for Information)

2. Submit RFIs for Every Discrepancy

• Example RFI: "Specification calls for VAV damper feedback, but mechanical drawing doesn't show damper actuator with position transducer. Please clarify."
• Get written response from design team before proceeding
• Don't assume—ask

3. Site Visit Before Programming

• Visit the site (even for 1–2 hours) to verify:
  • Equipment is actually installed
  • Wiring/cable exists and is accessible
  • Device locations match prints
  • Feedback sensors are present
• Take photos for documentation

4. Create an "As-Found" vs. "As-Designed" List

Document every difference between the original design and field reality:

DESIGN: AHU1 supply air temp sensor on discharge damper housing
AS-FOUND: No sensor—damper housing unreachable (blocked by ductwork)
RESOLUTION: Relocate sensor to return air plenum (approved by mechanical PE)

5. Request Change Orders for Scope Differences

• If significant changes (more than 10% of scope), document and ask for change order
• Don't just absorb the cost—pass it to client or subcontractor who caused the discrepancy

6. Get Owner Buy-In on Final Design

• Walk through the final controls logic and point list with owner/operator
• Confirm they understand what will be controlled and how
• Avoid surprises during startup