Ambitious NYC energy code framework approved

City Council sets parameters for future energy codes.

Published December 19, 2017

On December 19, 2017, the New York City Council approved Local Law 32, shaping the next three cycles of the New York City Energy Conservation Code. New requirements could drive energy savings of 30 percent or more in new construction by 2026, while transitioning the code toward a performance-based model.  

To be clear: The City Council did not enact a new energy code. Instead, it created parameters for the Department of Buildings (DOB) in developing future energy codes, which still must be submitted to the Council for approval.

Why is this legislation so important, then? Because once a new construction code has worked its way through DOB’s consensus process, the City Council typically passes it with only modest changes. Historically, deference tends to be even greater with energy codes—the Council enacted the last DOB-proposed update without any modifications.

A stretch code for 2019 and 2022

New York State has been developing a voluntary “stretch” energy code, NYStretch, and will soon start on its next code cycle. Today’s law requires DOB to match the future versions of these stretch codes in 2019 and 2022. If the stretch codes are not finalized for any reason, DOB must propose a new energy code that averages 20 percent energy savings over today’s code.^[1]While 20 percent may seem a big jump, right now it looks like the next version of ASHRAE will take care of the first 8 percent.

But NYStretch is well on its way, informed by a 25-member advisory team, extensive modeling and public comment. Overseen by NYSERDA, the state has nearly finalized the first stretch code based on the current energy code. It’s now turning to a future version based on the next code cycle, which would feed into DOB’s 2019 code update. The stretch codes include both prescriptive and performance-based paths, and, so far, the average savings over the current commercial code are coming in at 9 to 13 percent.^[2]Savings are weighted averages across building types, with some types saving more and others less.

Performance targets for large buildings in 2025

This legislation also telegraphs an important shift to come: performance-based codes. Beyond 2025, the law requires DOB to propose “predicted energy use targets” for buildings over 25,000 square feet.

With this approach, larger buildings would be able to meet the energy code by designing to a performance target. All they would need to show, through modeling, is how much energy the building will use in a year. If designed energy use is less than the specified target, then the building would meet the energy code.

This performance-based energy target framework promises greater simplicity, flexibility and ease of administration. It should reduce the time and cost of modeling both a baseline and proposed building.

The energy use targets will apply both to new construction and substantial renovation. They must be as stringent as practicable, achieving at least 30 percent average energy savings over today’s code, unless that stringency is deemed too burdensome. And, in a nod to its growing prevalence, the legislation caps the stringency of those targets at the Passive House standard.

But setting the right targets may require differentiation within building types for more intense space uses (like data centers or trading floors). And targets will need to be set with tenant variation in mind, including occupancy, plug load and hours of operation.

In part because of these challenges, Urban Green advocated (successfully) for an evidence-driven process to determine the best metrics and targets for this future framework, including stakeholder input, energy modeling, cost analysis and consideration of integrating green energy into a performance-based approach. This process will provide a necessary foundation to ensure that the development of future codes reflects both industry input and the city’s 80×50 goal.                  

As 2017 and the City Council session come to a close, this legislation looks to the decade ahead. The NYC green building community has much to celebrate as we ring in the new year!

Local Law 32 in brief

• Proposed code amendments in 2019 and 2022 must meet the most recent model stretch code developed by NYSERDA, provided that it is more stringent than the state code and published no more than three years prior.
• If no qualified stretch code exists in 2019 and 2022, proposed code amendments must ensure on average 20 percent energy savings over the 2016 New York State code, or a lesser savings if that stringency is found to be impractical or too burdensome.
• By January 2024, the DOB must publish a report, based on input from the code advisory committee, recommending predicted energy use targets for buildings over 25,000 square feet. The report must include recommendations on a metric and targets for different building types, energy modeling, sample designs, cost analysis, consideration of green energy, and implementation.
• In or after 2025, proposed code amendments must include predicted energy use targets based on the DOB report. The targets must be as stringent as practicable, ensuring on average at least 30 percent energy savings over the 2016 New York State code (or a lesser savings if that stringency is found to be impractical or too burdensome). The targets are capped at the Passive House standards in Local Law 31 of 2016.

Further Reading