What are the two phases for retrocommissioning in existing buildings?

• A. Planning and implementation
• B. Analysis and optimization
• C. Design and commissioning
• D. Scoping and execution

Answer: (A)

Retrocommissioning in existing buildings is carried out in two broad phases: planning and implementation. In planning, you define the project goals, gather and review building and system data, assess current operation, identify low-cost and feasible energy-saving opportunities, and develop a formal RCx plan that outlines scope, responsibilities, budget, and schedule. In implementation, the approved measures are carried out—tuning controls, adjusting sequences, changing operating schedules, calibrating equipment, and making any necessary configuration changes—followed by verification to ensure the expected savings are realized and the improvements are documented for ongoing operation. This structure fits RCx because the aim is to optimize existing systems and operations rather than undertake new design work.