NYC Local Law 97: What Building Owners Need to Know in 2026

New York City's Local Law 97 of 2019 is the most ambitious building-level carbon regulation in the United States. Enacted as the centerpiece of the NYC Climate Mobilization Act, LL97 sets legally binding greenhouse gas emissions intensity limits on most large buildings in the five boroughs — and imposes a statutory penalty of $268 per metric ton of CO2 equivalent (tCO2e) for every ton a building emits above its limit. For many building owners and managers, the law is now not a future concern but a present compliance obligation: the first reporting period covers calendar year 2024 emissions, with the first annual reports due May 1, 2025.

This guide covers everything NYC building owners and facilities managers need to understand: what the law requires, which buildings are covered, how emissions limits are calculated, what the penalties look like at realistic building scales, the compliance timeline through 2050, and the concrete strategies available to reduce emissions and achieve compliance — including energy efficiency retrofits, electrification, renewable energy, and available financial incentives.

1. What Is Local Law 97?

Local Law 97 of 2019 (LL97) was enacted by the New York City Council on April 18, 2019, as part of the broader NYC Climate Mobilization Act — a package of legislation designed to address climate change at the city level. LL97 is codified in the New York City Administrative Code as Chapter 3 of Title 28 (Sections 28-320.1 through 28-320.9).

The law establishes maximum annual carbon emissions intensity limits — expressed in metric tons of CO2 equivalent per square foot of gross floor area (tCO2e/sq ft) — for covered buildings, based on the building's occupancy type (use classification). Buildings that emit above their applicable limit in a calendar year are assessed the statutory penalty when they file their annual emissions report with the NYC Department of Buildings (DOB).

LL97 does not prescribe how buildings must reduce emissions — it sets a performance outcome (emissions below the limit) and leaves building owners to choose their compliance path. A building that installs heat pumps, one that invests in deep envelope upgrades, and one that purchases qualifying carbon offsets are all pursuing different paths to the same legal outcome. The law is outcome-based rather than prescriptive, which gives building owners significant flexibility but also significant responsibility for identifying and executing their own compliance strategy.

2. Which Buildings Are Covered

Local Law 97 applies to the following categories of buildings in New York City (per NYC Admin Code Section 28-320.1):

• Any building with a gross floor area exceeding 25,000 square feet
• Two or more buildings on the same tax lot that together exceed 50,000 square feet of gross floor area
• Two or more buildings held in the condominium form of ownership, governed by the same board of managers, whose aggregate floor area exceeds 50,000 square feet

The NYC Department of Buildings estimates that LL97 covers approximately 50,000 buildings citywide, representing roughly 60% of all building-related greenhouse gas emissions in New York City. The covered building stock is enormous and extraordinarily varied — it includes office towers, apartment buildings, hotels, hospitals, schools, warehouses, retail centers, and mixed-use developments.

Certain building types have modified compliance timelines or alternative pathways under LL97 rules, including: houses of worship; city-owned buildings; affordable housing buildings that meet specific low-income occupancy criteria; buildings under development agreements; and buildings subject to rent stabilization that fall within certain income-averaging provisions. These exemptions and modifications are detailed in DOB rule promulgations and should be evaluated with a licensed professional engineer familiar with LL97.

3. How Emissions Limits Are Set: The Carbon Intensity Framework

LL97's emissions limits are expressed as greenhouse gas intensity limits — maximum annual carbon emissions per square foot of gross floor area — and they vary by building occupancy type. The statute establishes two compliance periods with different (and progressively stricter) limits:

• First period: 2024–2029 — Relatively modest limits designed to capture the most carbon-intensive buildings and establish the reporting and compliance infrastructure
• Second period: 2030–2034 — Significantly stricter limits, approximately 40% lower than the first-period limits for most occupancy types, intended to drive deep decarbonization across the covered building stock

Selected Emissions Intensity Limits (per LL97 Section 28-320.3.2)

Source: NYC Administrative Code Section 28-320.3.2 (LL97 text). Limits shown for selected primary occupancy types; mixed-use buildings with multiple occupancy groups calculate a blended limit weighted by floor area. Consult the full statute and NYC DOB rule guidance for complete occupancy type listings and mixed-use calculation methodology.

How to Calculate Your Building's Annual Emissions

A building's annual greenhouse gas emissions under LL97 are calculated using the following framework (per LL97 Section 28-320.3.1):

For each fuel or energy type consumed in the building, multiply the annual quantity consumed by the applicable greenhouse gas emission factor published by NYC DOB in its rules. Sum those products. Divide the total by the building's gross floor area in square feet. Compare the resulting intensity figure (in tCO2e/sq ft/yr) to the applicable limit for the building's occupancy type(s).

The emission factors used in this calculation are set by NYC DOB rule and are updated periodically. Critically, the emission factor for grid electricity consumed in NYC has been projected to decline over time as Con Edison and the New York grid (NYISO) become cleaner under state renewable energy mandates — meaning buildings that electrify their heating will benefit from improving grid emission factors over the 2024–2050 compliance horizon, even without changing their equipment. NYC DOB published projected electricity emission factors through 2050 in its LL97 rulemaking.

4. Penalties: What Non-Compliance Costs

The LL97 penalty structure is straightforward and significant. Under NYC Administrative Code Section 28-320.6, a building owner who submits an annual emissions report showing emissions above the applicable limit — or who fails to submit a report at all — is assessed a civil penalty of $268 per metric ton of CO2 equivalent by which the building's reported emissions exceeded its applicable limit for that calendar year.

To illustrate the financial stakes, consider two representative examples:

Example 1: Commercial Office Building, 150,000 sq ft

The 2024–2029 emissions intensity limit for commercial office buildings is 0.00846 tCO2e/sq ft/yr (per LL97 Section 28-320.3.2). For a 150,000-square-foot office building, the annual emissions limit is 0.00846 × 150,000 = 1,269 tCO2e per year.

If the building's actual 2024 emissions — calculated from utility bills using DOB emission factors — come in at 1,600 tCO2e, it exceeds the limit by 331 tCO2e. The annual penalty is 331 × $268 = $88,708 for calendar year 2024 alone.

Example 2: Multifamily Residential Building, 80,000 sq ft

The 2024–2029 limit for multifamily residential (R-2) is 0.00675 tCO2e/sq ft/yr. For an 80,000-square-foot building, the annual limit is 540 tCO2e. A building currently exceeding this limit by 100 tCO2e per year faces a penalty of 100 × $268 = $26,800 per year — sustained until emissions are reduced below the limit.

5. Compliance Timeline

• 2019
  April 2019 — LL97 Enacted

  NYC Council passes Local Law 97 as part of the Climate Mobilization Act. Governor and Mayor sign. Compliance obligations established for buildings over 25,000 sq ft.
• 2024
  January 1, 2024 — First Compliance Year Begins

  Calendar year 2024 is the first year for which emissions are measured against LL97 limits. Buildings begin accumulating annual emissions liability under the first-period intensity limits (2024–2029).
• 2025
  May 1, 2025 — First Annual Emissions Reports Due

  First annual building emissions reports covering calendar year 2024 must be filed with NYC DOB by May 1, 2025. Reports must be certified by a registered design professional (licensed architect or engineer). Buildings over their limit face penalties assessed upon report filing.
• 2026
  2026 — Second Annual Reports Due; Ongoing Compliance Period

  Annual reports for calendar year 2025 due May 1, 2026. Buildings operating in the first-period compliance window (2024–2029). Penalties accumulate annually for buildings over their limits. Capital improvements planned now will be operational by 2027–2028.
• 2030
  January 1, 2030 — Stricter Second-Period Limits Take Effect

  Second compliance period (2030–2034) begins with significantly stricter emissions intensity limits — approximately 40% lower than first-period limits for most occupancy types. Many buildings currently in compliance will require additional decarbonization measures to remain compliant.
• 2035
  2035 and Beyond — Further Tightening

  LL97 requires NYC DOB to establish limits for subsequent five-year compliance periods (2035–2039, 2040–2044, 2045–2049) through rulemaking, each period progressively reducing allowable emissions toward the 2050 net zero goal.
• 2050
  2050 — Net Zero Carbon Goal

  LL97's ultimate target: covered buildings in NYC achieve net zero greenhouse gas emissions by 2050. Emissions limits for the final compliance period will be set to effectively require net-zero performance.

6. Compliance Strategies: From Quick Wins to Deep Decarbonization

Building owners have multiple pathways to LL97 compliance, ranging from operational measures and controls upgrades to full building electrification. The right strategy depends on the magnitude of your building's emissions gap, your budget and financing capacity, lease structure and tenant relationships, and your planning horizon through 2030 and beyond.

• 1

  Energy Efficiency Retrofits: HVAC, Lighting, and Envelope

  For buildings that are modestly over their first-period limits, or that need to reduce emissions before more extensive capital programs are completed, targeted energy efficiency upgrades often provide the fastest and most cost-effective path to compliance. HVAC controls optimization — including economizer controls, variable air volume (VAV) improvements, and building automation system (BAS) upgrades — can reduce building energy use 10–20% with relatively modest investment. LED lighting retrofits reduce lighting energy consumption 50–70% and carry payback periods of 2–4 years in commercial buildings. Building envelope improvements (insulation, window sealing, air barrier upgrades) reduce heating and cooling loads, directly cutting both energy consumption and emissions. Get a free energy audit to identify the highest-impact efficiency measures for your specific building.

• 2

  Electrification: Replacing Fossil Fuel Heating with Heat Pumps

  For most New York City buildings, the largest source of on-site greenhouse gas emissions is combustion of natural gas or fuel oil for space heating and domestic hot water — not electricity consumption. LL97's emission factors assign relatively high carbon intensity to natural gas combustion (and especially to fuel oil), while the emission factor for grid electricity in NYC is projected to decline substantially as New York state achieves its renewable energy mandates. This structural dynamic means that electrification of heating systems is the highest-impact single compliance measure for most fossil fuel-heated buildings. Air-source heat pumps, water-source heat pumps, and geothermal heat pump systems are all viable options depending on building type and configuration. For multifamily buildings still using steam heating systems — common in pre-war NYC apartment buildings — electrification requires more extensive planning and often includes a transition to hydronic (hot water) distribution, but the emissions reduction is substantial. See our natural gas vs. heat pump comparison for a detailed analysis of the emissions and economics of electrification in NYC.

• 3

  On-Site Solar and Renewable Energy

  On-site solar photovoltaic generation directly offsets grid electricity consumption, reducing the purchased electricity that contributes to a building's LL97 emissions calculation. For NYC buildings, rooftop solar can typically provide 5–15% of a building's total annual electricity consumption depending on roof area and building load profile. On-site solar does not directly offset the natural gas combustion emissions that are the primary LL97 compliance challenge for most buildings — its value is most significant in buildings where electricity represents the primary emissions source, or as a complement to electrification measures that shift heating load to electricity. New York State's NY-SUN Incentive Program provides incentives for commercial solar installation. Con Edison's commercial net metering tariff governs the billing treatment of excess generation. See our New York commercial energy guide for current NY-SUN incentive levels.

• 4

  Greenhouse Gas Offsets

  LL97 allows building owners to use qualifying greenhouse gas offsets to reduce their calculated annual emissions for compliance purposes, subject to limits and criteria established in NYC DOB rules. Qualifying offsets must meet specific additionality, permanence, and verification requirements, and must come from approved offset project types. The offset option provides a compliance bridge for buildings where capital retrofits are underway but not yet complete — owners can purchase offsets to cover any remaining emissions gap in transition years. However, offsets are not a long-term substitute for actual emissions reductions: the law's increasingly stringent limits, combined with the declining availability of high-quality offsets, make physical decarbonization the only durable compliance strategy through 2050.

• 5

  Community Solar Subscriptions and Virtual Net Metering

  For buildings where on-site solar is not feasible — due to roof area constraints, historic preservation restrictions, or structural limitations — community solar subscriptions and Con Edison's virtual net metering program provide an alternative path to claiming renewable energy benefits. A community solar subscription credits your utility bill based on output from a shared solar facility elsewhere in the Con Edison service territory. Under LL97 rules, credits received through Con Edison's community distributed generation (CDG) program may reduce the grid electricity emissions attributed to your building. Consult a licensed professional engineer or LL97 compliance advisor to confirm the current DOB rule treatment of community solar credits in emissions calculations.

7. Financial Incentives That Reduce Compliance Costs

The capital investment required to achieve LL97 compliance — particularly for buildings targeting the stricter 2030–2034 limits — is substantial. Federal, state, and utility incentive programs can meaningfully reduce the net cost of required improvements.

Inflation Reduction Act (IRA) Federal Tax Credits

The IRA, signed into law in August 2022 and currently in effect, provides significant federal tax incentives for commercial building energy improvements that are directly relevant to LL97 compliance:

• Section 179D Energy Efficient Commercial Buildings Deduction: A federal tax deduction for qualifying energy efficiency improvements to commercial buildings, including HVAC, lighting, and building envelope upgrades. The base deduction is $0.50 per square foot, scaling up to $5.00 per square foot for improvements meeting prevailing wage and apprenticeship requirements. For a 150,000-square-foot building, the maximum deduction at $5.00/sq ft represents $750,000 in federal tax benefit. See our IRA energy credits guide for 2026 eligibility and claim procedures.
• Section 48 Investment Tax Credit (ITC) for Solar: A 30% federal investment tax credit for qualifying commercial solar photovoltaic installations, with potential bonus credits for domestic content and energy community location. A $500,000 solar installation in New York City could generate a $150,000 federal tax credit under the base ITC rate.
• Section 48E ITC for Standalone Storage and Heat Pumps: The IRA extended investment tax credits to standalone energy storage systems and commercial heat pump water heaters, relevant to electrification and grid resilience investments at covered NYC buildings. Use our IRA calculator to model applicable credits for your planned improvements.

PACE Financing

Property Assessed Clean Energy (PACE) financing allows commercial building owners to finance energy efficiency and renewable energy improvements through a property tax assessment, repaid over 5–25 years. PACE financing is off-balance-sheet for many building owners, eliminates the upfront capital requirement for LL97 compliance improvements, and transfers with the property on sale. New York State's commercial PACE program (C-PACE) is administered through the New York State Energy Research and Development Authority (NYSERDA) and available to NYC commercial property owners. C-PACE is particularly useful for financing the full cost of heat pump conversions, building envelope improvements, and solar installations that may not qualify for conventional commercial lending given their size or payback period.

Con Edison and NYSERDA Utility Incentives

Con Edison's commercial incentive programs — including rebates for high-efficiency HVAC equipment, LED lighting, building controls, and demand response participation — can reduce the installed cost of qualifying energy efficiency measures by 10–30%. NYSERDA's Commercial Energy Efficiency Programs offer technical assistance, financing, and incentives for commercial buildings pursuing deep energy retrofits. The NYC Accelerator program, operated in partnership with NYSERDA and the NYC Mayor's Office of Climate and Environmental Justice, provides free technical assistance and expedited permitting support for buildings pursuing LL97 compliance — a significant resource for building owners navigating the complexity of compliance planning for the first time. Our commercial energy benchmarking guide covers how to assess your building's current performance relative to LL97 requirements and available incentive programs.

Frequently Asked Questions