Local Law 97: Building Emissions Reduction

Understanding NYC's groundbreaking climate law, why it was created, and how to prepare your building for increasingly strict carbon emission limits through 2050.

What is Local Law 97?

Local Law 97, enacted in 2019 as part of the Climate Mobilization Act, establishes carbon emission limits for buildings over 25,000 square feet—covering approximately 50,000 buildings in NYC. It is one of the most ambitious climate policies in the United States, requiring the city's largest buildings to dramatically reduce global warming emissions. The law sets specific emission intensity limits (measured in kilograms of CO2 equivalent per square foot per year) that buildings cannot exceed. These limits become progressively stricter over time, with major reductions required by 2030, 2035, and continuing through 2050. Buildings that exceed their limits face substantial annual penalties.

Why This Law Exists

Unlike in many cities where transportation dominates emissions, New York's dense building stock and extreme climate (very hot summers, cold winters requiring heavy heating) make buildings the primary culprit for climate action. Local Law 97 was created to address the climate crisis by targeting the largest contributors to emissions. The law aligns with New York City's commitment to reduce greenhouse gas emissions 80% by 2050 (known as 80x50) and ultimately achieve carbon neutrality. Without dramatic action on building emissions, the city cannot meet its climate goals.

The law also recognizes that climate change poses severe risks to New York City—from sea level rise threatening coastal areas, to extreme weather events like Hurricane Sandy causing billions in damage. By reducing emissions now, the city aims to mitigate future climate impacts while positioning itself as a global leader in urban climate action.

Who Must Comply?

Buildings subject to Local Law 97:

Covered buildings: Properties over 25,000 gross square feet, including:

  • Residential buildings with 35+ units (roughly 25,000 sq ft or larger)
  • Commercial office buildings
  • Hotels
  • Mixed-use properties
  • Most institutional buildings

Exemptions and special provisions:

  • Rent-regulated affordable housing (with income restrictions) receives higher emission limits.
  • Houses of worship, certain industrial facilities, and city-owned buildings have different requirements or exemptions.

Key Compliance Periods

Local Law 97 phases in gradually, giving building owners time to plan and implement energy efficiency improvements. However, the limits become significantly stricter over time.

2024-2029: First Compliance Period

Buildings must meet initial emission limits based on building type and occupancy. Annual reporting required by May for each year showing total emissions and compliance status. Penalties begin for buildings exceeding limits in 2024.

These initial limits are achievable for many buildings with no major upgrades, but buildings with older, inefficient systems or those relying heavily on fossil fuels will need to make improvements.

2030-2034: Second Compliance Period

Dramatically stricter limits take effect January 1, 2030. These limits represent approximately a 43% reduction from 2005 baseline levels. Most buildings will need significant energy efficiency upgrades to comply. The 2030 limits are where Local Law 97 "gets real"—very few buildings can meet them without substantial investment.

Buildings should begin planning for 2030 compliance now. Waiting until 2029 means rushed decisions, higher costs, and potential inability to complete necessary work in time.

2035-2039: Third Compliance Period

Further reductions required as the city continues toward 80% reduction by 2050. Specific limits to be determined but will be even lower than 2030-2034 period.

2040-2049: Fourth Compliance Period

Approaching near-zero emissions, relying primarily on the city's grid for carbon neutrality. Buildings will need to be nearly entirely electric or use carbon-neutral energy sources.

2050: Goal Year!

NYC aims for 80% reduction in greenhouse gas emissions from 2005 levels, with a pathway toward full carbon neutrality by beyond 2050.

The 2030 Cliff

Many building owners focus only on the current 2024-2029 limits, which are relatively achievable. But the 2030 limits represent a massive jump in stringency. Buildings that barely comply in 2029 will face huge penalties starting in 2030 without a major improvement. You need to plan for 2030 compliance now, not in 2029.

How Emission Limits Work

Local Law 97 sets building emission intensity limits measured in kilograms of carbon dioxide equivalent per square foot per year (kgCO2e/sf/year). Each building type has different limits based on typical energy use patterns.

2024-2029 Emission Limits (Selected Building Types)

Building TypeOccupancy GroupLimit (kgCO2e/sf/year)
Multifamily HousingGroup R-26.75
Office BuildingsGroup B8.47
HotelsGroup R-19.87
RetailGroup M11.38
Assembly (theaters, etc.)Group A10.04

2030-2034 Emission Limits (Selected Building Types)

Building TypeOccupancy GroupLimit (kgCO2e/sf/year)
Multifamily HousingGroup R-24.07
Office BuildingsGroup B4.89
HotelsGroup R-15.51
RetailGroup M6.33
Assembly (theaters, etc.)Group A5.60

Note the dramatic decrease from 2024-2029 to 2030-2034. For example, multifamily buildings drop from 6.75 to 4.07 kgCO2e/sf/year—a 40% reduction. This is why most buildings will need significant retrofits.

Mixed-Use Buildings

Buildings with multiple occupancy types (e.g., ground floor retail with residential above) have limits calculated proportionally based on the square footage of each use. The emission limit is the weighted average of all occupancy types in your building.

Calculating Your Building's Emissions

Every covered building must calculate and report its annual carbon emissions based on energy consumption. This is not an estimate—it's based on your actual utility bills.

Energy Sources and Their Emissions

The calculation includes all energy used in your building:

  • Electricity: Emissions depend on the grid mix (fossil fuels vs. renewables). NYC's grid has been getting cleaner over time, so more renewable energy means lower emissions, which helps buildings reduce emissions even without changes.
  • Natural Gas (for direct emissions from combustion): This is typically the largest source of a building's emissions, especially for heating. Every therm of natural gas burned creates approximately 11.7 kg CO2e (or 0.0117 metric tons).
  • District Steam: NYC's steam system, primarily in Manhattan, provides heating and hot water. Emissions are based on how the steam is generated.
  • Fuel Oil (if applicable): Some older buildings still use oil for heating. This has very high emissions and buildings should prioritize converting away from oil.

Annual Reporting Requirement

All covered buildings must file an annual emissions report by May 1st through the NYC Department of Buildings online portal. The report must be prepared by one of the following:

  • Registered Design Professional (licensed architect or engineer)
  • Certified Energy Auditor
  • High-Performance Building Design Professional
  • Approved third-party verifier

The report includes your building's total emissions, your emission limit, whether you're in compliance, and any compliance strategies you are using (e.g., renewable energy credits or building improvements).

Penalties for Non-Compliance

Local Law 97 has real financial teeth. Buildings that exceed their emission limits face substantial annual penalties that can quickly exceed the cost of compliance measures.

Penalty Structure

$268 per metric ton of CO2e over the limit (adjusts annually for inflation). This penalty applies every year you exceed your limit.

Example Penalty Calculations

Small multifamily building (50,000 sq ft)

  • 2030 limit: 4.07 kgCO2e/sf/year = 203.5 metric tons total
  • Actual emissions: 5.4 kgCO2e/sf/year = 270 metric tons
  • Overage: 66.5 metric tons
  • Annual penalty: $17,822
  • Every-year cost (2030-2034): $89,110

Large office building (200,000 sq ft)

  • 2030 limit: 4.89 kgCO2e/sf/year = 978 metric tons total
  • Actual emissions: 7.0 kgCO2e/sf/year = 1,400 metric tons
  • Overage: 422 metric tons
  • Annual penalty: $113,096
  • Every-year cost (2030-2034): $565,480

Penalties Often Exceed Retrofit Costs

Many building owners discover that five years of penalties can more than pay for energy efficiency upgrades needed to achieve compliance. Plus, efficiency upgrades cut operating costs, while penalties are just fees. Investing in compliance usually makes financial sense beyond just avoiding penalties.

Additional Penalties

  • Failure to file annual report: Separate violation and penalties
  • False or misleading reports: Significant fines and potential professional discipline for the certifying professional
  • Compounding effects: Penalties continue every year until compliance is achieved

Strategies for Compliance

Most buildings will need a combination of strategies to meet LL97 limits, especially the stricter 2030 requirements. The right approach depends on your building's specific characteristics, current systems, and budget.

Energy Efficiency Upgrades

These are the foundation of most compliance strategies:

HVAC System Improvements

  • Boiler replacement: Replace old, inefficient boilers with high-efficiency condensing boilers (92%+ efficiency vs. 70-80% for older units)
  • Heat pump installation: Electric heat pumps for heating and cooling can dramatically reduce emissions, especially as the grid gets cleaner.
  • System controls: Smart thermostats, zone controls, and building management systems optimize operation.
  • Distribution improvements: Insulate pipes, balance heating system, fix steam traps.

Building Envelope Upgrades

  • Window replacement: Install high-performance windows with low-E coatings and improved insulation.
  • Insulation: Add insulation to roofs, walls, and exposed surfaces.
  • Air sealing: Reduce drafts and air leakage that waste heating and cooling.
  • Roof improvements: Cool roofs or green roofs reduce cooling loads.

Domestic Hot Water

  • Heat pump water heaters: Much more efficient than gas or electric resistance.
  • Solar thermal: Use sun to preheat water, reducing gas/electric use.
  • Insulation: Insulate pipes and storage tanks to reduce heat loss.

Lighting and Plug Loads

  • LED lighting: Replace all old lighting with LEDs (75% less energy).
  • Lighting controls: Occupancy sensors, daylighting, dimming systems.
  • Energy Star appliances: In residential buildings, upgrade common area and in-unit appliances.

Alternative Compliance Pathways

Local Law 97 provides some flexibility beyond just reducing building emissions.

Renewable Energy Credits (RECs)

Buildings can purchase RECs to offset some emissions. However, there are strict limits—RECs can only offset up to 10% of your emission limit. This means RECs alone cannot achieve full compliance; you must still reduce actual building emissions significantly.

On-Site Renewable Energy

Solar panels on your roof or other on-site renewable generation directly reduce your building's grid electricity use and associated emissions. For buildings with suitable roof space, solar can be highly cost-effective, especially with available tax credits and incentives.

Greenhouse Gas Offset Projects

In limited cases, buildings can invest in qualified offset projects. However, regulations are strict and this is not a primary compliance strategy for most buildings.

AKME's Approach to LL97 Compliance

We help buildings develop comprehensive compliance strategies that balance immediate needs with long-term goals. Our process includes:

  • Energy audit and emissions modeling to understand your current status
  • Financial analysis of saving, costs, savings, penalties avoided, and return on investment
  • Prioritized upgrade recommendations based on cost-effectiveness and impact
  • Coordination with qualified energy consultants and contractors—we're transparent, pricing and deliverables
  • Access to financing and incentive programs to improve project economics
  • Ongoing monitoring and annual reporting to track progress

Our CFO-level financial expertise ensures you understand the full picture—not just project costs, but energy savings, penalty avoidance, property value impacts, and financing options. We help you make informed decisions that protect your investment.

For more information

Official Local Law 97 page