Retro-commissioning
Retro-commissioning is the commissioning of an existing building that was never commissioned and in many cases it is considered building “tuning”. The retro-commissioning process starts with reviewing any design information that is available to determine a baseline for how the building was designed to operate. After this process the actual operation is observed through site evaluation and data gathering which provides the information for the commissioning agent to evaluate and begin to “tune” the building.

Building Tuning

Tuning of building systems makes sure they are working at an optimized point. It is a process that typically occurs over a year of operational observation to verify the system operation during the various seasons. Part of the process includes working with the building maintenance staff and educating them on how to maintain the systems at that optimized point.

Benefits of Retro-commissioning

•	Lower Energy Usage
•	Increased Occupant Comfort
•	Extended Equipment Life
•	Better Indoor Environmental Quality
•	Lowered Maintenance Costs

Re-commissioning

With commissioning complete on a building it is important to re-commission the building on a continual basis. This should occur every 3 to 5 years. With the documentation complete from the new building commissioning or retro-commissioning process, the re-commissioning is typically a shorter process that involves verification that the systems are still operating at an optimized point and that maintenance is occurring as it should.