Systems-based retrofit strategies have significant energy-savings potential, providing anywhere from 49% to 82% in additional energy savings compared to component-only upgrades.1,2 Until now, few studies have explored how often American businesses include systems-based retrofits in their energy and sustainability investments. After examining a dataset of 12,000 retrofit projects, the U.S. Department of Energy’s (DOE’s) Building Technologies Office (BTO) and Lawrence Berkeley National Laboratory (LBNL) found that while system retrofits represent less than 20% of all retrofit projects, they are twice as common in projects with higher overall energy savings.

The study, “Systems Retrofit Trends in Commercial Buildings: Opening Up Opportunities for Deeper Savings,” provides a framework for categorizing systems approaches. It defines a systems-based retrofit as going beyond a single component (such as a lamp or chiller) by incorporating additional elements or controls within an end-use system or using passive or active controls for interaction with other building components or end-use systems.

Infographic: Systems-based retrofit strategies. Courtesy of Lawrence Berkeley National Laboratory.

Systems-based retrofit strategies. 

Courtesy of Lawrence Berkeley National Laboratory.

LBNL’s researchers evaluated the dataset―which contained information from utility custom retrofit programs, federal government retrofit programs, and energy service company retrofits―to identify the following:

  • How often system retrofits are occurring
  • The most prevalent technologies used in these retrofits
  • Whether system retrofits save more energy than component retrofits
  • How these different programs are successful in deploying system retrofits

This research, led by FLEXLAB® Executive Director Cynthia Regnier, shows that system retrofits in commercial buildings are critical to achieving aggressive energy-reduction goals. Forty percent of projects with high energy savings were found to include system retrofits, while only 16% of projects with low energy savings included systems retrofits. Additionally, there were notable differences in the success of each program type in deploying system retrofits. Utilities lagged behind other programs, relying heavily on lighting-system retrofits. Mechanisms such as energy savings performance contracts (ESPCs), on the other hand, achieved deeper levels of energy savings and made use of a wider range of strategies, including HVAC system retrofits.

The study includes interviews with a range of stakeholders, which shed light on barriers to further uptake and increased deployment. The interviews show that system retrofits could be expanded through increased awareness of their energy-savings potential, technology and process improvements to reduce complexity of design, installation and operation, and, in some cases, removal of policy barriers that require individual measures of cost-effectiveness, which can be incongruent to a system that is cost-effective as a whole.

This work complements ongoing research on the benefits associated with commercial building technologies. To learn more about BTO’s efforts to improve energy efficiency in the country’s 5.6 million commercial buildings, visit

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1 Regnier, C., K. Sun, T. Hong, and M.A. Piette. “Quantifying the benefits of a building retrofit using an integrated system approach: A case study.” Energy and Buildings 159 (2018).

2 Regnier, C., P. Mathew, A. Robinson, P. Schwartz, J. Shackelford, and T. Walter. 2018. Energy Savings and Costs of Systems-Based Building Retrofits: A Study of Three Integrated Lighting Systems in Comparison with a Component Based Retrofit. Lawrence Berkeley National Laboratory.