Outcome-based commercial-building energy codes are an idea gaining new interest among policymakers in the United States. This type of energy code prescribes building energy budgets instead of a complex list of requirements. The first efforts started 10 years ago, and we are still years away from a model sure to gain significant adoption. Due to the concept’s potential benefits, however, it is possible, if not likely, that outcome-based codes will be a tool in future energy regulation.
Energy codes are a cost-effective way to increase energy efficiency in buildings. Buildings designed and constructed according to the latest energy codes and standards are about 37 percent more-efficient than those built 15 years ago. Lighting and controls have played a significant part in achieving these energy savings. Energy codes regulate lighting design by setting lighting power density limits and requiring certain types of lighting controls.
A challenge for codes is that increasing energy savings has been accompanied by increasing complexity, which can make compliance confusing and difficult. Exacerbating this problem is the fact that the United States has a national reference energy standard (ANSI/ASHRAE/IES 90.1) but no mandatory energy code. This has resulted in a patchwork of unique local, regional and state energy codes that may include elements based on the national reference standard, the International Energy Conservation Code (IECC), or both. For policymakers, a problem is energy codes regulate building design and installed features, making energy savings a matter of prediction instead of measurement.
One potential path forward for energy codes is outcome-based codes.
Building energy-code compliance is typically based on a prescriptive/mandatory approach where the building is designed with a set of power limits and mandatory features like lighting controls. An alternate compliance method is performance-based, which involves many of the same mandatory requirements plus intensive energy modeling in lieu of some prescriptive measures. Outcome-based energy codes are different.
“Outcome-based energy codes use a building’s actual, measured/metered energy performance as the compliance metric,” said Cori Jackson, program director for the California Lighting Technology Center at UC Davis and president of the California Energy Alliance. “They can eliminate all of the complex and lengthy prescriptive requirements and replace these with a list of energy budgets by building type and/or application.”
For building owners and designers, the main benefit is simplicity, fewer conflicts during installation, and more freedom to produce a building that satisfies occupant needs. For contractors, they could face less confusion stemming from plans and specifications that contradict code requirements. For code inspectors, verification may also be simplified by allowing them to inspect energy use information provided by the building owner. For policymakers, outcome-based energy codes mean true progress toward energy goals could finally be measured.
Under an outcome-based code, lighting control adoption may undergo significant change due to a shift of incentives.
Currently, lighting controls feature in codes as mandatory requirements, which have become increasingly dense even as lighting power densities have declined. The emphasis is on room-based systems capable of implementing multiple, layered control strategies.
Under an outcome-based code, Jackson said demand for lighting controls would increase substantially, with a greater emphasis on building-level control systems that feature energy measurement capability and the ability to fine-tune operation to achieve compliance on an ongoing basis.
“I think the overall trend toward smart buildings and Internet of Things is here to stay, and outcome-based codes will only drive that further into the mainstream,” she said. “But as for specific controls in buildings, that will be building/application specific. Both local and centralized control systems will continue to have their benefits and be used in areas where they make sense.”
Because of their attractiveness to policymakers—they can regulate energy consumption and verify savings as opposed to regulating initial design and estimating savings—the idea of outcome-based codes has a lot of support. They will likely be implemented initially by progressive states like California for new construction and be offered as a flexible and simplified compliance option.
Various jurisdictions have experimented with outcome-based codes. In the United States, examples include the cities of Seattle and Boulder. In Seattle, a measured performance option was added to the energy code, but due to a lack of sufficient incentives, adoption was minimal. In Boulder, outcome-based codes focus on periodic building retrocommissioning, mandatory lighting upgrades, and other measures.
The biggest potential proponent is Jackson’s home state of California, but the California Energy Commission’s regulating authority is currently limited to design and not building operations, which necessitates a change to state law.
Otherwise, significant challenges must be resolved to identify a model most likely to meet with success. Enforcement is one such issue (e.g., what happens if the owner fails to comply based on equipment that is already installed in a finished building), and ultimately, the designer may have to produce intensive energy modeling to give the owner confidence they will comply with their energy budget.
“Outcome-based codes will simplify the energy code compliance process and significantly increase the use of building controls and automation,” Jackson said. “Outcome-based codes will give the electrical industry back the flexibility to design and construct useful structures instead of constructing buildings to meet a list of requirements that may not be useful to anyone once the building is in operation.”
She encouraged industry stakeholders in California to get involved by reaching out to the California Energy Alliance, adding, “Get involved if outcome-based codes sound like something that will improve your business or building.”