Commercial retro-commissioning is similar to getting your car serviced regularly. There are systems in the buildings (heating, air conditioning, lighting etc.) that may be performing well when they are installed but over time things go wrong and may or may not be fixed. That is, unless you perform a regular analysis and inspection of the equipment. Retro-commissioning is a systematic process that identifies performance issues with a buildings’ equipment and creates a plan or process to rectify these issues. The most important recommendations that usually come out of this type of a program include modifying equipment scheduling and setpoints. Reducing the time that a building is heated or cooled and changing the temperature settings to hotter or colder (depending on the season) can have an enormous impact on energy use.