Existing building commissioning (EBCx), also known as retrocommissioning (RCx), is a systematic process applied to your existing building or buildings to improve overall system operations. Depending on the age of the building, existing building commissioning will resolve problems that occur during design or construction, and address problems that have developed throughout the building’s lifetime. In all, existing building commissioning improves building efficiency, boosting overall building performance, translating into energy savings.

The skill sets needed for existing building commissioning are different from your standard commissioning project. Because the commissioning agent must have the skill sets to troubleshoot and interrogate a control system, or read out an HVAC system, or do a performance test on chillers, to name a few examples. Buildings that generally work at less than desired performance — usually a attributed to the building's age — are excellent candidates for existing building commissioning. It could be high energy output, poor occupant control, or a combination of many factors.

CBWDTA-BuildingFor the building shown, which is the downtown Kansas City airport, we provided retrocommissioning services and fixed what we could to make the systems at far more comfortable for the occupants. Moving forward, we completely replaced the entire HVAC system with zero downtime to the building and its occupants. sys-tek provided design,construction management, commissioning, and balancing for the entire project from start to finish. Retrocommissioning is a science which requires a special skillset, much like surgery or IT.

If you are missing just one of the skillsets, your chances of success diminish, and the team that provides the services must know what to look for and how to test and interrogate systems for controllability and performance. Unlike new building commissioning, there are no contractors or other engineers to write an issue log for someone else to solve. On existing building commissioning projects, we provide the solutions.


Existing building commissioning will:

  • Bring equipment to its optimal operating efficiency
  • Reduce energy demands and cost
  • Reduce complaints
  • Increase occupants’ satisfaction and comfort
  • Increase equipment life
  • Improve indoor environmental quality
  • Reduce staff time spent on emergency call
  • Improve facility operation
  • Decrease your monthly fixed costs
  • Improve yearly equipment budget forecasting

EBCx cost allocation

  • 69% planning and investigation
  • 27% implementation
  • 4% verification, tracking and reporting

Cost Savings: Existing building commissioning can produce significant cost savings in existing buildings. Savings will vary depending on the building type, its location, and the scope of the existing building commissioning performed.

sys-tek has been providing EBCx services for 18 years in healthcare, higher education, life sciences, mission critical, and industrial facilities.

Retrocommissioning Purchase Guide

Our Purchase Guide to Retrocommissioning will tell you everything you need to know about finding the right retrocommissioning agent for your facility.

Download Now