The 2025 New York Energy Conservation Code (2025 NYCECC) goes into effect March 30, 2026. It is intentionally more stringent than the 2020 NYCECC, as it seeks to deliver approximately 10-15% additional energy savings (depending on building type) and explicitly supports carbon and emissions reductions under Local Law 97 (the New York City Climate Mobilization Act).
Whether your project will be immediately impacted depends on what stage it’s in; consult our most recent blog post for details. Eventual compliance is inevitable, though, so project owners and architects are advised to familiarize themselves with the differences between the two code versions.
What Is Different in the 2025 NYCECC?
Electrification & Fossil Fuel Restrictions
Perhaps the most consequential difference in the two versions relates to fossil fuels. While the 2020 NYCECC did not directly address fuel types and generally permitted gas-fired systems if they were considered to be efficient, the 2025 NYCECC expressly prohibits the use of fossil fuel-combustion systems in new constructions (with several exceptions). The 2025 NYCECC also expresses a strong preference for heat pumps and electrically heated water and requires coordination with Local Laws 154 and 97.
Mechanical Systems
The 2025 NYCECC mandates higher minimum HVAC equipment efficiencies and includes expanded heat recovery requirements. Owners are encouraged to incorporate more advanced mechanical system controls, like demand-based ventilation, and follow tighter fan power limitations.
Lighting
Lower lighting power density (LPD) limits are established by the 2025 NYCECC. Expanded use of networked lighting controls, daylighting, and automatic shutoffs are encouraged.
Building Envelopes
If you’ve read this far, you won’t be surprised to learn that the 2025 NYCECC also requires higher insulation values for roofs, walls and slabs, and more stringent window and curtain wall performance. Owners should be considering continuous insulation, thermal bridge mitigation, and air leakage control and verification.
Energy Modeling
While the 2020 NYCECC focused on prescriptive paths for energy modeling, the 2025 NYCECC expands the role of performance-based compliance. Modeling assumptions are tightened, and trade-offs that might have been acceptable under the 2020 NYCECC will no longer pass muster. Owners are expected to see greater scrutiny of unmet load hours and system interactions.
Commissioning
Projects subject to the 20205 NYCECC will see more systems subject to functional testing. More documentation and more extensive sign-off requirements will be necessary, and the New York City Department of Buildings (DOB) will have enhanced enforcement authority over the outcomes.
How Will the 2025 NYCECC Impact My Project?
The answer to this question is one that applies to most code changes: budget and timeline. The 2025 NYCECC seeks to solve important environmental challenges that we face, and the planned outcome of these changes is a cleaner, healthier city for all. However, that doesn’t mean that they will be easy changes. Certain requirements will cost more to meet than under the 2020 NYCECC, and sourcing and commissioning can potentially add significant time to the project. We recommend that owners and architects begin exploring solutions and approaches now to be better prepared for the (imminent) future.
