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Retro Commissioning Definition

Retro-Commissioning is the application of the same process to existing buildings. Retro-commissioning is a process that seeks to improve how building equipment and systems are operating and functioning together. Depending on the age of the building, retro-commissioning can often resolve problems that occurred during design or construction, or address problems that have developed throughout the building's life. In all, retro-commissioning improves a building's operations and maintenance (O&M) procedures to enhance overall building performance. 

It is a collaborative process that looks at how and why building systems are operated and maintained. It then identifies ways to improve overall building performance.

  • A systematic process for improving and/or optimizing an existing building's operation and energy consumption profile.
  • An adaptive process that meets the current operational needs as closely as possible.
  • The process may include remedial design and construction to accomplish this goal. /li>

Abbreviation for Commissioning is: RCx

Benefits of Retro-Commissioning

  • Lower Energy Consumption (typically 5% - 20% of total building energy costs)
  • Reduced Operating Expenses
  • Implementation Payback of 2 years or Less
  • Improved Occupant Comfort
  • Improved Indoor Air Quality
  • Increased Occupant Productivity
  • Improved Operations and Maintenance
  • Extended Equipment Life
  • Energy Equipment Performance
  • Increased Owner Profitability
  • Lower Carbon Emissions and Greenhouse Gases
  • Facility Staff Training (Informal & Formal)

Commissioning Standards and Guidelines

  • Associated Air Balance Council (AABC) Commissioning Group (ACG) Guidelines
  • Association of Energy Engineers (AEE) Standards
  • United States Green Building Council (USGBC) Standards
  • National Environmental Balancing Bureau (NEBB) Guidelines
  • American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) Guidelines
  • American Institute of Architects (AIA) Standards


  • Sheet Metal and Air Conditioning Contractors' National Association (SMACNA) Standard
  • U.S. Department of Energy Commissioning for Federal Facilities
  • U.S. General Service Administration (GSA) Building Commissioning Guide
  • U.S. Veterans Administration (VA) Standards
  • USACE / NAVFAC / AFCEC / NASA Unified Facilities Guide Specifications (UFGS) Standard
  • World Building Design Guide (WBDG) Specifications
  • National Fire Protection Association (Standard 3, Fire Systems Commissioning) Standard
  • American Society for Testing and Materials (ASTM) Standard
  • International Code Council (ICC) Standard
  • International Green Construction Code (IGCC) Guideline