Globally, energy codes are recognized as one of the most cost-effective policy tools for promoting energy efficiency in buildings. In the United States, the latest codes and standards overall require a minimum 37% higher level of efficiency than 15 years ago. Lighting has played a major role in achieving these energy savings, typically implemented with a design satisfying lighting power limits and mandatory controls.
On the downside, codes are complex and sometimes confusing, sometimes requiring interpretation by the authority having jurisdiction. Because there is no national code, the country is a patchwork of codes. Energy codes only regulate design efficiency and are therefore limited to being predictive of energy savings based on estimates and modeling.
Going back more than a decade, some policymakers began working to simplify energy codes while addressing their shortcomings. Instead of a prescriptive-based (design within limitations, with some mandatory items) or performance-based (intensive modeling) compliance path, codes would evolve to be outcome-based, using a building’s actual measured/metered energy performance as the compliance metric.
While outcome-based codes remain some years away due to significant hurdles, they remain an attractive goal for policymakers and may be introduced during this decade. They’d likely start in progressive states such as California, targeting new construction and offered as an option for building owners, with design flexibility and simplified compliance documentation being major enticements.
“Outcome-based codes can eliminate complex and lengthy prescriptive requirements and replace this with a list of energy budgets by building type and/or application,” said Cori Jackson, program director for the California Lighting Technology Center at UC Davis and board chair of the California Energy Alliance.
For designers, an outcome-based code would be freeing. No longer would they need to comply with hundreds of pages of requirements. Instead, they would simply design a building that satisfies owner needs and operates within a given energy budget. Contractors would continue to install specified devices and systems, but potentially with less risk.
“I think there will be a reduction in the confusion that comes when plans and specifications contradict the energy code requirements,” Jackson said.
Controls will be key, she added, because they provide a high degree of flexibility in managing energy consumption on an ongoing basis. Current codes often emphasize room-based solutions. With an outcome-based code, building owners will be incentivized to adopt a building-level system capable of detailed energy measurements and fine-tuning control parameters.
Despite these merits, there will be initial difficulties in implementing and enforcing an outcome-based energy code. How does the jurisdiction verify compliance, and what happens if energy consumption rises above the code limit during a certain time of the year?
“There are a lot of details to work out among stakeholders before an outcome-based code could be deployed broadly,” Jackson said.
Enforcement could become much simpler for code officials, who would no longer be required to verify long lists of mandatory building features. For example, officials could verify energy-use information provided by the building owner, similar to required energy benchmarking data currently reported to the state of California.
Various jurisdictions have experimented with the concept, notably in cities such as Seattle and Boulder, Colo. In Seattle, regulators added a measured performance option to its energy code, but the requirements’ complexity resulted in lackluster adoption. This provided a lesson that to be accepted, outcome-based codes must live up to their promise of simplicity.
Boulder took a different approach, requiring periodic retrocommissioning, mandatory lighting upgrades and other measures.
One would think California—one of the most progressive in terms of energy efficiency—would be experimenting. However, the California Energy Commission (CEC), the regulating authority, is limited in what it can do by law. For the CEC to adopt an outcome-based code, the Warren-Alquist Act would need to be amended to allow energy regulations based on building operations and not just design.
Over the past 20 years, commercial building energy codes have profoundly changed lighting design and technology. As these codes approach what may be maximum source energy savings, policymakers are increasingly interested in simplifying them to increase compliance while being able to measure actual, ongoing energy savings versus estimated savings. Outcome-based codes offer one such solution, but significant challenges remain in determining the right formula that would enable widespread adoption.