At a Glance


Industrial Goods and Manufacturing

Project Type

Industrial Energy Efficiency




Norwalk, CT

Savings icon

Annual kWh Savings:

500,000 kWh

Reductions icon

Annual CO2 Reductions:

249 metric tons


David Rengel evaluated the costs and benefits of retrocommissioning at Xerox.


David Rengel spent his summer at Xerox Corporation, a global enterprise in the business process and document management space with over 130,000 employees worldwide in 160 countries. An MBA candidate from the University of Michigan, Rengel joined the Site and Facilities Services Energy Team at Xerox's campus as a Climate Corps fellow tasked with evaluating retrocommissioning as a means to reduce energy consumption of the campus.


Retrocommissioning, also known as existing buildings commissioning, is an engineering process to analyze building systems and equipment and return them to design or a more efficient condition based on current building use. As part of the process to evaluate the costs and benefits of retrocommissioning for Xerox, Rengel implemented a pilot project for a small complex of four buildings with the objective of reducing energy use of the buildings. The pilot project will serve as a demonstration of how to proceed with expanding the scope to include the entire campus. Preliminary results from the retrocommissioning study found 36 building deficiencies that, when corrected, would reduce energy use.

Potential Impact

Rengel identified energy savings amounts to electricity reductions totaling over 500,000 kWh/year, over 15,000 therms of natural gas per year, CO2 emissions reductions of 249 metric tons, and over $66,000/year savings. The pilot successfully demonstrated the cost effectiveness of retrocommissioning, and significantly greater energy and cost savings are possible with full campus retrocommissioning.

Related Links