“ASHRAE Guideline 0.2-2015 Commissioning Process for Existing Systems and Assemblies”
requires the following items as part of Retro-Commissioning:

• Define Owner’s EBCx goals and objectives.
• Select the Initial EBCx Team.
• Collect and analyze historical energy use.
• Study the building and its operational characteristics with regard to energy use, occupant health and productivity, and equipment and structural reliability and longevity.
• Develop CFR
• Review building documentation such as building plans, specifications, O&M manuals, and maintenance records.
• Perform diagnostic monitoring and establish trend logs to documents building performance for several weeks.
• Visually inspect systems for correct installation and operation.
• Perform simple repairs required to keep equipment operating, reduce energy use, and allow more accurate data gathering such as trend logging.
• Perform functional tests.
• Identify potential modifications that will reduce energy use and/or cost (includes a descriptions of the measure, estimated energy savings, cost estimate, and simple payback).
• Perform an engineering and economic analysis of potential modifications.
• Prepare a rank-ordered list of appropriate modifications.
• Implement recommended modifications.
• Prepare the draft EBCx Report, which includes the Implementation Report.
• Revise O&M procedures to improve efficiency and equipment longevity.
• Update facility personnel training programs for current and revised systems. Implement retraining of O&M staff as required.
• Transition to Ongoing Commissioning (OCx) with the OCx Plan. Ensure persistence of benefits with measurement and verification (M&V) strategies such as trend logging and monitoring.
• Prepare the final EBCx Report, including the Lessons Learned Report.

Definitions:
CFR: Current Facility Requirements
EBCx: Existing-Building Commissioning
M&V: Measurement and Verification
OCx: Ongoing Commissioning
O&M: Operation and Maintenance