Moving Daylighting into a New Era

Note: To celebrate our 20th Anniversary we’ve invited energy efficiency leaders who have partnered with NBI to share their stories and successes. In this post, Nancy Jenkins Ander, P.E., Deputy Director, Office of Sustainability, Department of General Services, reflects on the influential research that helped discover the advantages of daylighting in schools, offices, and retail.

In the energy efficiency world, we know that if there are specific and tangible non-energy benefits to energy conserving measures, it can be a game changer to motivating the implementation of these measures. One example of this is the work and research performed on the connection between daylighting and productivity.

How PIER research helped guide the way
In 1999, Lisa Heschong, with Heschong Mahone, carried out research that scientifically examined this connection focusing on productivity, such as heightened learning in school environments and increased sales in retail environments. Around that same time, AB 1890 passed in California, restructuring the electric industry and establishing a Public Interest Energy Research (PIER) Program administered by the California Energy Commission (CEC). At PIER, we didn’t want to just do more incremental research. We wanted to find those critical voids that needed to be filled and make a difference in applications research. The PIER Program management made a decision to take some risks in broadening our scope to go beyond the traditional hardware research and instead embraced the opportunity to develop a holistic research agenda that focused broadly on softer areas of research such as behavioral research. We all knew that lots of eyes were on the program with high expectations. Without taking some risks into these unproven areas, we could be giving up the chance to break important ground.

Partnering with NBI and connecting the dots
New Buildings Institute (NBI) recognized the huge potential represented in Lisa’s early research, that correlated daylighting to productivity. They saw the need to focus and follow-up on the study to deepen the data pool, provide additional rigorous data analysis, scientifically establish correlations that appeared to exist, and proposed a significant research effort to advance this important work.

Productivity findings from the research were startling. In 2017, the findings may seem obvious but 10 years ago it was astonishing to learn. In the Daylighting in Schools Study, we found that increasing daylighting levels from “average” to “maximum” increased learning rates by 11%. Through different variables it was also discovered that daylighting showed a strong correlation to improved learning. In fact, the findings contributed to the Los Angeles Unified School District’s decision to adopt the Collaberative for High Performance Schools (CHPS) guidelines, resulting in increased use of daylighting in new schools.

For retail structures, our Daylighting and Retail Sales research revealed that daylit stores found a 0-6% increase in sales compared to non-daylit stores. During times when the retail chain in the study operated its stores at half lighting power, the daylit stores had an average 5.5% increase in sales relative to non-daylit stores. In offices, the research found that daylighting was a significant and positive predictor of better performance on a test of mental function and attention.

What next?
The NBI/Heschong PIER research provided a much needed focus on investigating non-energy impacts of a key energy conserving measure (daylighting) and provided the scientific rigor to validate a clear correlation that since that time has influenced owners and designers to look holistically at the value of daylighting and apply it more broadly in building design.

Separately, NBI also saw a propensity in the industry to design commercial HVAC systems for functionality, but not necessarily optimal efficiency of all system elements. They proposed research on integrated HVAC system design that would specifically address the energy elements of the system. The program took a much needed deep dive into the energy elements of HVAC system design to draw out and emphasize those design elements that directly impact energy use and can be optimized without sacrificing performance of the system.

This research program was a key part of the holistic approach PIER took at exploring how to advance energy efficiency from broader behavioral, codes and design perspectives.

In the past 10 years many of the participants in this early PIER research, from retailers to schools as well other organizations, have successfully acted on the findings and the work continues to influence the design of retail, school, office and other built environments today.

by Nancy Jenkins AnderDepartment of General Services