New York City adopts new energy conservation code, aims to reuse existing buildings

New York City has adopted the 2025 NYC Energy Conservation Code based on the 2024 International Energy Conservation Code (IECC) and the NYC Existing Building Code, which is based on the International Existing Building Code (IEBC).

The main objective of the NYC Existing Building Code is to preserve and reuse existing buildings by offering flexible compliance options.

The new code also aims to:

• Simplify the current complex regulatory structure 
• Provide clear guidance for the 80,000+ alteration applications filed annually 
• Eliminate obstacles to rehabilitating existing buildings 
• Promote compliance by making the code easier to navigate 
• Provide energy code updates that reflect statewide progress

Key updates include: 

• Mandatory air‑leakage testing for all buildings 
• Enhanced requirements for backup electric heating and supporting resilience during extreme weather events 
• Alignment with modern national standards that promote energy efficiency, reliability, and long‑term cost savings