Illuminating Energy Savings

The complex landscape of energy efficiency is constantly developing according to research, experience, and best practices that are shared industry wide. As such, there are a number of moving parts that go hand in hand to contribute to more energy efficient buildings and energy savings, including heating, cooling, electricity, and lighting- which plays a critical role in both energy consumption and occupant experience.

Energy Star launched Portfolio Manager as a resource management tool, enabling building owners to benchmark energy use in a secure online environment. Energy Star Portfolio Manager is a powerful tool for buildings to benchmark their energy performance, implement energy saving measures, and earn recognition through the Energy Star Certification program. Cities nationwide are beginning to pass ordinances that require that commercial buildings benchmark their electric and gas performance through Portfolio Manager. In fact, nearly 25% of commercial building space in the United States is already benchmarking using Portfolio Manager. It also helps track progress toward certification. At Energy Sciences, we have helped clients of varying sizes and needs, benchmark and certify their buildings utilizing this program.

Buildings that are Energy Star Certified are held to rigorous standards, contributing to energy efficiency and emissions goals nationwide. Lighting plays a key role in both efficiency and occupant comfort, making lighting standards especially important for certified buildings. Energy Star Certified buildings follow standards from the Illuminating Engineering Society of North America (IESNA) Lighting Handbook, which recommends horizontal and vertical task illuminances for a wide range of spaces.

The Illuminating Engineering Society (IES) is the global authority on illumination and is accredited by the American National Standards Institute (ANSI). The IES drafts, publishes, and maintains over 100 standards for lighting in buildings and outdoor facilities. All of these standards aim to enhance spaces through improving the quality of lighting. These standards emphasize the importance of proper illumination, which affects many aspects of work and leisure. Quality lighting design aesthetically contributes to visual performance and comfort, improves public safety, and promotes wellness. It also increases lighting system reliability, reduces energy consumption, and gives building owners the authority to control unwanted lighting. As the lighting landscape has evolved rapidly in recent years, proper illumination has become one of the pillars in helping achieve energy goals regardless of project scale. The shift from incandescent lightbulbs and fluorescent lamps to LEDs has increased cost-effectiveness and allowed buildings to become more energy efficient. Still, to improve lighting in the commercial landscape, the IES is constantly working to move the industry forward. To best deliver information and best practices about illumination, the standards are written by subject matter experts in a variety of committees.

Energy Sciences team members who have membership with the IES find the resources and buildings invaluable to the work they are doing. Energy Sciences’ IES member Niesh Streeter explains,

“Our Lighting Team utilizes the IES handbooks and written standards on a daily basis. While we regularly adhere to the standard commercial design elements, we often face challenges involving unique spaces or human-centric considerations that require more than just a “standard” approach. Having access to the correct research and tools, allows our team to effectively find solutions, while maintaining high quality, energy efficient lighting, and adhere to the most up to date industry recognized energy standards.”

The IES writes the technical documents that serve as authoritative benchmarks for lighting quality – the defined measure of lighting within spaces, performance models, and industry standards. They are developed by large, cross-functional teams including government actors, industry professionals, academics, and members of the public to implement quality lighting. As lighting quality increases through these standards, they enhance comfort, aesthetics, and workability across many types of facilities. These standards are reviewed and updated annually by volunteer technical committees to address any new developments in the industry.

For Energy Star Certification, applicable IES standards identify horizontal and vertical illuminance targets in specific building types, depending on the use of the space. For example, in a common commercial space like a lobby, there is a general target of 10 foot-candles (fc), which is a lighting intensity measured at the floor or walking plane, while spaces such as meeting rooms have horizontal targets of 30 fc which are measured at the task or working plane. The lighting target ranges from 5 fc to over 100 fc, and measurements are required at either horizontal or vertical planes, depending on the type of facility and the specific use of the space. There are also requirements in place to maintain comfort and safety, which benchmark uniformity ratios (maximum: minimum or average: minimum), or allow for variation of measured light levels depending on the demographic of the people utilizing the spaces. Energy Star Certification requires auditors to confirm that any building aiming to be certified meets the published IES standards.

Together, IES lighting standards and ANSI/ASHRAE/IES Standard 90.1 underscore the critical role illumination plays in overall building energy performance. Older lighting technologies and poorly controlled systems waste energy by converting excess electricity into heat, increasing cooling loads and straining building systems. Modern standards address these challenges by pairing high‑efficiency light sources with advanced controls strategies that optimize light levels based on space use and occupant needs. Beyond aesthetics, quality lighting improves safety, visual comfort, and productivity while supporting measurable energy savings. By aligning lighting design and operation with established IES guidance and the efficiency requirements of Standard 90.1, commercial buildings are better positioned to achieve energy performance goals and earn recognitions such as Energy Star Certification.

At Energy Sciences, we are ready and excited to help you meet the prescribed lighting requirements for your commercial facilities!

Co-Written by Katie Percha, Alexis Southerland, and Niesh Streeter