Major Steps Involved in
Retro-Commissioning:

Benchmark energy use

• Review utility bills
• Compare energy usage with similar buildings

Site Investigation

• Review HVAC, lighting and other energy-consuming systems
• Monitor energy usage with meters
  
• System performance testing

Identify energy conservation measures

• Catalog all potential measures
  
• Determine life cycle costs (payback)
  
• Prioritize measures
  

Implement measures

• Work with engineers and/or contractors to prepare construction documents
  
• System verification
• Operation and warranty reviews