Retrocommissioning Technicians analyze and optimize existing building systems such as HVAC, lighting, and controls using diagnostic tools and monitoring systems. They identify inefficiencies and implement improvements. Responsibilities include system testing, analysis, troubleshooting, and reporting. Work environments include existing commercial buildings and facilities. They follow energy standards and retrocommissioning protocols. Their role improves energy efficiency, reduces operational costs, and enhances system performance, making them essential in sustainable building operations globally.