The Art Rosenfeld Award for Energy Efficiency supports UC Berkeley graduate students doing innovative research in technologies and policies that will enable a more resource-efficient society. Since receiving the 2025 Art Rosenfeld Award, Aoyu Zou, a PhD student at UC Berkeley’s Center for the Built Environment, has continued his work creating standardized frameworks for energy-efficient building retrofits and advancing new ways to measure and verify building performance.
Beyond the Retrofit: Making Efficiency Measurable
With the award’s support, Zou and his collaborators have expanded their research network and laid the groundwork for field demonstrations that apply automated re-commissioning and diagnostic tools in existing buildings. The planned experiments will focus on demonstrating how these tools can enhance the energy efficiency of existing buildings, which is an essential step to ensure that retrofit measures remain effective over time. In June, Zou presented elements of this research at the REHVA HVAC World Congress CLIMA, the leading international scientific conference on heating, ventilation, and air conditioning, which brings together experts from across academia and industry to share advances in building performance and climate-responsive design.
Energy efficiency in buildings goes beyond a one-time innovation; it also depends on making progress measurable. “Our research aims to emphasize that improvements cannot be managed if they cannot be measured or quantified accurately,” Zou said. Zou’s research focuses on ensuring that improvements are sustained, developing practical methods to monitor how buildings operate after retrofits and to confirm that savings persist over time. He and his team recently completed a study which evaluated advanced heat pump water heater controls in approximately 20 Bay Area homes, and showed how improved measurement frameworks can increase accuracy in savings estimates. “We envision our work contributing to the evaluation of retrofit performance,” he said, “which can serve as a foundation for future energy policy frameworks and incentive programs.”
Building an Efficient Future for All
For Zou, this work builds directly on the legacy of Dr. Art Rosenfeld, whose career redefined how data and design can drive smarter energy use. “The recognition and visibility from the award have led to valuable collaborations and constructive feedback, which have helped refine my research objectives and scope of work,” he shared. By focusing on energy efficiency and flexibility as cost-effective retrofit strategies for existing buildings, Zou’s research helps the benefits of efficiency—lower emissions, cleaner air, and healthier spaces—reach communities across California. In advancing how we measure and sustain building performance, he is helping move the state closer to a future where energy systems are efficient, reliable, and accessible to all.