The Federal Energy Management Program’s Building Re-tuning Simulator (BRS) allows users to estimate energy, cost, and CO₂ emission savings from implementing various re-tuning™ measures in their buildings. Users create a simplified building model that estimates impact from selected simulations using the available heating, ventilation, and air conditioning control measures, operations and maintenance measures, and capital project measures.

Because federal buildings account for nearly 60% of the energy used in the United States, re-tuning presents a significant opportunity to optimize buildings to save energy and reduce CO₂ emissions. Using the outcomes from the BRS simulation will help building and energy managers identify the re-tuning measures that can optimize their building’s operations, improve comfort, and reduce energy use and CO₂ emissions in a low-cost manner. Previous re-tuning efforts at federal sites have resulted in energy savings ranging from 5% to 25%, with a simple payback of 0.3–3.5 years.