The energy code in force for New York City projects in 2026 is the 2025 New York City Energy Conservation Code (2025 NYCECC), together with the 2025 NYC ASHRAE 90.1. The NYC Department of Buildings (DOB) began enforcing both on March 30, 2026. If your application for construction document approval came in on or after that date, the 2025 edition governs your design, your energy analysis and your inspections. This guide explains which edition applies to your job, what the code asks for, what you file, and who on the project team carries which part.
TL;DR
- The 2025 NYCECC and 2025 NYC ASHRAE 90.1 were adopted through Local Law 47 of 2026 and have been enforced by DOB since March 30, 2026.
- Filings made with complete documentation before March 30, 2026 stay under the 2020 NYCECC. Filings made on or after that date, and incomplete earlier filings, fall under the 2025 code.
- Compliance is shown through an EN filing in DOB NOW: a professional statement, an energy analysis, a supporting documentation index, TR8 progress inspection information and, where applicable, commissioning information.
- New York State's 2025 code took effect statewide on December 31, 2025, and the city code cannot be less stringent than it.
- Owners, architects and contractors each touch the energy filing, so settle the energy scope before drawings are finalized, not at permit review.
Table of Contents
- Which energy code applies in New York City in 2026
- Which edition governs a project caught in the transition
- What the code covers
- What you file to prove compliance
- Who does what on the project team
- Enforcement and what happens when a filing falls short
- Our perspective: design for the filing, and for the next decade
- Getting your project through the 2025 code
- FAQ
Which energy code applies in New York City in 2026
New York City writes its own energy code rather than adopting the state code unchanged. The 2025 NYCECC is the current edition, and DOB's Energy Conservation Code page confirms enforcement of the 2025 NYCECC and 2025 NYC ASHRAE 90.1 beginning March 30, 2026.
The city code sits on top of a state floor. The New York State Department of State says the 2025 Energy Conservation Construction Code of New York State (ECCCNYS) and 2025 NYS ASHRAE 90.1 became effective statewide on December 31, 2025. State law requires every local energy code, including the NYCECC, to be no less stringent than the ECCCNYS. In practice the city can go further than the state, never softer.
That gap between December 31, 2025 and March 30, 2026 is a common source of confusion. DOB deferred enforcement of the new city code until updated compliance software platforms were ready, a point DOB addressed in a 2026 Buildings Bulletin. So a project could sit in a window where the state code was already effective while the city was still reviewing under the 2020 NYCECC. For anything filed today, that window is closed.
Which edition governs a project caught in the transition
The edition depends on when your application was filed and how complete it was, not on when you break ground or when the work finishes. DOB's guidance sets out three cases:
| Situation | Edition that applies |
|---|---|
| Filed with complete documentation before March 30, 2026 | 2020 NYCECC |
| Filed on or after March 30, 2026 | 2025 NYCECC or 2025 NYC ASHRAE 90.1 |
| Filed before March 30, 2026 but incomplete (no complete energy analysis, or pre-filing status) | 2025 NYCECC |
The third row catches people. A job number that predates March 30 does not protect you if the energy analysis was not complete when it was filed. If you have a project in this gray area, pull the filing record and check what was actually submitted, then confirm the edition with your engineer of record before you price equipment or order long-lead items.
Post-approval amendments deserve the same attention. A change in scope that adds mechanical, lighting or envelope work can change what the energy analysis must show. Ask your design team whether the amendment is consistent with the edition already governing the filing.
What the code covers
The state code, which the city code must at least match, applies to new commercial and residential buildings, additions, alterations, and renovations of existing buildings and building systems. The NYCECC follows the same structure, and the 2025 edition is based on the 2024 International Energy Conservation Code with New York City amendments. Reported changes in the 2025 update include new efficiency credits, broader requirements for existing buildings and updated provisions for historic buildings, so do not assume a design that passed under 2020 will pass unchanged.
What the code regulates, in plain terms:
- Building envelope: insulation, fenestration, air barriers and air leakage.
- Mechanical systems: heating, ventilating and air conditioning equipment efficiency, controls, ductwork and piping insulation.
- Service water heating: equipment efficiency and distribution.
- Lighting and power: interior and exterior lighting power, controls and metering.
- Commissioning: verification that systems perform as designed, where the code requires it.
What existing buildings must and must not do
Alterations are where owners and contractors most often over- or under-comply. The state's guidance on alteration exemptions, written for the 2020 state code, makes the logic clear: the code does not require unaltered portions of an existing building or system to comply. Energy Law § 11-103(1)(b) is the basis. It lists specific exemptions as well, including storm windows, glass-only replacement in existing sash and frames, and lighting alterations that replace less than 50 percent of luminaires as long as installed interior lighting power does not increase.
For additions and alterations, the Department of State has also noted that a full inspection of the envelope, especially insulation and the air barrier, is often more practical than a blower-door metric such as ACH 50, which was designed with new construction in mind. Expect your inspector and your engineer to talk in terms of what was touched, not the whole building.
Two practical rules follow from that:
- Define the work area precisely. Energy compliance attaches to what you alter, so a clear scope on the drawings limits what must be upgraded.
- Do not stretch an exemption. Replacing a boiler, a rooftop unit or a hot water heater is not a glass-only or lighting-count exemption. Equipment replacements usually trigger efficiency and controls requirements.
A note on fossil-fuel provisions
The state's 2025 code included provisions restricting fossil-fuel equipment installations. The Department of State's FAQ says those provisions remain suspended by court order and are neither effective nor enforceable, and that the Department will monitor the case. Because this is a litigation-dependent point, ask your engineer to confirm current status before you lock in fuel choices for a boiler or domestic hot water plant.
What you file to prove compliance
Energy code compliance in New York City is a documented filing, not a checkbox. DOB's NYCECC FAQ describes the EN filing as including:
- A professional statement from the filing professional
- An energy analysis
- A supporting documentation index
- TR8 progress inspection information
- Commissioning information, where applicable
- Required energy code calculations, reports or narratives
Supporting documents go through DOB NOW, and they must align with the work types, scope and progress inspections you filed. DOB's guidance for the 2025 code also says the construction documents must show that proposed energy design elements meet or exceed code, support the energy analysis, and match the filed scope.
Choosing the energy analysis method
DOB requires an energy analysis, and its FAQ describes three kinds of submissions: a simple tabular analysis, COMcheck, and energy modeling. The right one depends on the project.
| Method | Typical fit |
|---|---|
| Tabular analysis | Small, prescriptive scopes such as a limited alteration |
| COMcheck | Commercial work where the prescriptive path can be documented in software |
| Energy modeling | Larger or more complex projects, or designs that trade off between systems |
Choose early. A design that cannot hit a prescriptive value in one area, say a lower-performing envelope assembly on a historic facade, may need a modeling path to make up the difference elsewhere. Finding that out after permit objections costs weeks.
Keep drawings and the analysis in step
The most common cause of energy objections is mismatch: the mechanical schedule lists equipment efficiency that differs from what the analysis assumed, the lighting plan shows more fixtures than the lighting power calculation counted, or the filed work types do not cover what the drawings show. Treat the energy analysis as a live document that is updated whenever a schedule or plan changes, not a form produced at the end.
Who does what on the project team
Building owners and property managers. You decide scope and budget, and you carry the consequences of a bad filing. Settle early whether you are replacing equipment, altering a space or doing a full renovation, because that sets which parts of the code are triggered. If you are planning capital work, ask for an equipment condition review first so replacements are sequenced rather than done piecemeal, each triggering its own review.
Architects. Envelope assemblies, glazing, air barrier continuity and lighting layouts come from you, and they feed the analysis. Coordinate your assemblies with the engineer's calculations before drawings are issued for filing, and make sure the energy documentation index matches your sheet list.
HVAC and boiler contractors. Efficiency ratings, controls and commissioning requirements affect what you can install. Submit product data that matches the scheduled equipment. A substitution that lowers a rated efficiency can break the energy analysis, so route substitutions through the engineer of record before you order.
Plumbers. Service water heating, pipe insulation and recirculation controls fall under the code. Confirm the heater type and efficiency in the plumbing design and tell the engineer if field conditions force a change.
The engineer of record. The engineer prepares or reviews the analysis, signs the professional statement, and stands behind the filing through progress inspections. Because the code is design-driven, this person's decisions at schematic stage matter more than any fix at the end.
Enforcement and what happens when a filing falls short
DOB enforces the energy code through plan review of the construction documents and through progress inspections tied to the TR8 information in your filing. If the energy analysis is incomplete or the documents do not match the filed scope, you can expect objections that hold up approval, and you can expect inspectors to compare installed work with what was approved. Work that departs from approved documents can lead to stop-work conditions, failed inspections and costly rework, so the cheapest compliance is the one designed in from the start.
The code is also separate from the city's building emissions law. Local Law 97 sets carbon emission limits for buildings over 25,000 square feet, with a published penalty of $268 per metric ton of excess emissions. A project can satisfy the energy code and still leave a building exposed under Local Law 97, which is why an equipment replacement is a good moment to look at both together. Boiler and HVAC upgrades designed only to pass the energy code may not be the ones that bring a building's emissions into line.
Our perspective: design for the filing, and for the next decade
We have spent years working with NYC agency procedures, and the pattern is consistent: energy code problems are rarely about a single hard requirement. They are about timing and coordination. The edition question, the analysis method, the equipment schedule and the filed scope all have to line up, and each is owned by someone different.
Three habits prevent most of the trouble we see:
- Decide the edition on day one. Look at the filing date and the completeness of what was filed, and write down which code applies. Do not discover it at review.
- Pick the analysis path before you finalize equipment. If modeling is likely, you want the model informing the design, not defending it afterwards.
- Treat equipment replacement as a compliance event. A boiler or plant upgrade touches the energy code, the fuel question and, for larger buildings, Local Law 97. Planning those together costs less than three separate fixes.
Because our mechanical, plumbing and fire protection engineers work in-house, those trade conflicts get resolved at one table instead of passed between consultants. Owners deal directly with senior engineers, which matters when a filing needs a quick judgment call rather than a ticket in a queue.
— Joseph
Getting your project through the 2025 code
If you have a filing coming up, we can review your scope, confirm which code edition governs it, and prepare the mechanical, plumbing and fire protection design and the DOB filings that go with it. Owners and managers planning boiler, HVAC or plant work can start with our building owner services, and design teams that need permit support can see how we handle NYC permit filing. For the full range of disciplines, see our engineering services.
FAQ
What energy code does New York City use?
New York City uses the 2025 New York City Energy Conservation Code and the 2025 NYC ASHRAE 90.1, enforced by DOB since March 30, 2026. The city code must be no less stringent than the 2025 state code, which took effect statewide on December 31, 2025.
Does my project fall under the 2020 or the 2025 code?
If you filed with complete documentation before March 30, 2026, the 2020 NYCECC applies. If you filed on or after that date, or you filed earlier without a complete energy analysis or in pre-filing status, the 2025 NYCECC applies. Check your filing record with your engineer of record.
What documents show energy code compliance?
The EN filing in DOB NOW includes a professional statement, an energy analysis, a supporting documentation index, TR8 progress inspection information, and commissioning information where applicable. The energy analysis can be a simple tabular analysis, COMcheck or an energy model, depending on the project.
Do alterations to an existing building have to bring the whole building up to code?
No. State law and the Department of State's guidance say unaltered portions of an existing building or system are not required to comply. The work you alter must comply, subject to listed exemptions such as glass-only replacement or limited lighting changes.
Is the energy code the same as Local Law 97?
No. The energy code governs how a building or alteration is designed and built, and you show compliance in a DOB filing. Local Law 97 sets annual carbon emission limits for larger existing buildings and is a separate compliance obligation.