LL97 Carbon Credits: Can RECs and Offsets Actually Help Your Building?
New York City building owners are under growing pressure to reduce greenhouse gas emissions. Local Law 97 (LL97) has made building carbon emissions a major compliance issue, especially for large commercial and multifamily properties.
One question comes up often: Can carbon credits, Renewable Energy Credits (RECs), or carbon offsets help a building meet its LL97 requirements?
The short answer is yes, but only in specific situations.
LL97 does not treat every carbon credit or offset as a valid compliance tool. The type of credit, where it comes from, when it was generated, and how it is applied all matter. For some buildings, credits can help reduce an emissions gap. For others, relying too heavily on credits may not solve the underlying problem of inefficient equipment, high energy use, or fossil fuel consumption.
What Is Local Law 97?
New York City’s Local Law 97 is one of the most important building emissions regulations in the country. It was enacted as part of the Climate Mobilization Act and establishes greenhouse gas emissions limits for many buildings in New York City.
Covered buildings generally include buildings over 25,000 square feet, although specific compliance pathways and requirements vary by building type and circumstances. LL97 establishes increasingly strict emissions requirements over different compliance periods.
For many property owners, the challenge is straightforward: If a building’s annual emissions are above its applicable limit, the owner needs to take action.
That action may include energy efficiency upgrades, electrification, renewable energy, qualified deductions, offsets, or other compliance options permitted under LL97.
What Are LL97 Renewable Energy Credits?
A Renewable Energy Credit, or REC, represents the environmental attributes associated with one megawatt-hour of electricity generated from a renewable energy source.
However, building owners cannot simply purchase any renewable energy certificate available on the market and assume it will qualify for LL97.
NYC’s LL97 REC policy has specific eligibility requirements. Qualifying RECs must be associated with resources considered by the New York Independent System Operator (NYISO) to be capacity resources located in, or whose output directly sinks into, New York City’s Zone J for the applicable reporting year.
This distinction is important.
A generic renewable energy certificate purchased from a project somewhere in the United States may support renewable energy in a broader sense, but that does not automatically make it eligible for Local Law 97 compliance.
The City has also identified specific REC categories, including Tier 4 RECs, as relevant to LL97. Tier 4 RECs are associated with projects intended to bring additional renewable electricity into New York City.
Can RECs Reduce Your LL97 Emissions?
Yes, qualifying RECs can potentially provide a deduction from reported electricity-related building emissions.
But there is an important limitation.
RECs address electricity emissions. They do not erase on-site fossil fuel emissions.
For example, imagine a commercial building that uses electricity from the grid but also burns natural gas for heating. Purchasing qualifying RECs may help with the building’s eligible electricity emissions, but it does not eliminate emissions created by the building’s gas boilers.
That means a property with significant natural gas, fuel oil, or other fossil fuel consumption cannot expect RECs alone to solve its LL97 compliance problem.
This is one of the biggest misconceptions about LL97 carbon credits.
What About Carbon Offsets?
Carbon offsets work differently from RECs.
A carbon offset generally represents a quantified reduction or avoidance of greenhouse gas emissions from a project. Instead of directly reducing emissions at the building buying the credit, the money supports an eligible project that reduces emissions elsewhere.
However, LL97 has taken a very specific approach to offsets.
Under current NYC rules, the only greenhouse gas offsets eligible for LL97 compliance are offsets purchased through the Affordable Housing Reinvestment Fund (AHRF) Offsets Program. NYC Buildings states that the maximum allowable deduction is 10% of a building’s calculated emissions limit.
This means property owners should be very careful when someone offers to sell them generic “carbon credits” for LL97 compliance.
A voluntary carbon offset may have environmental value, but that does not necessarily mean it is an LL97-approved offset.
How Do AHRF Offsets Work?
The Affordable Housing Reinvestment Fund provides a more localized approach to carbon offsets.
Money from the sale of AHRF offsets supports qualifying decarbonization projects in affordable housing buildings in New York City. These projects can include building electrification and other improvements designed to reduce greenhouse gas emissions.
AHRF offsets are designed around principles such as additionality, uniqueness, verification, and robust emissions baselines. The program also tracks offset purchases and retirements through a registry.
This creates an important difference between a standard voluntary carbon offset and an LL97-compliant carbon offset.
The goal is not simply to buy a certificate. The program is designed to connect the financial value of the offset with real emissions reductions in New York City’s building sector.
Are Carbon Credits Better Than Building Upgrades?
Usually, no.
For most property owners, the strongest long-term strategy is to reduce emissions at the building level first.
Consider a building with aging boilers, inefficient HVAC equipment, poor controls, and high electricity consumption.
Buying credits may help address part of the immediate compliance gap. But the building could continue to face high utility costs and increasing emissions requirements in future compliance periods.
Energy efficiency and electrification can address the source of the problem.
Potential improvements may include HVAC upgrades, boiler replacement, building controls, lighting improvements, heat pumps, building envelope improvements, improved insulation, domestic hot water upgrades, energy recovery systems, on-site solar, and battery energy storage.
The right combination depends on the building’s size, age, equipment, occupancy, energy profile, and LL97 compliance pathway.
This is why a proper LL97 building emissions assessment should come before purchasing credits.
RECs vs. Carbon Offsets: What’s the Difference?
Although RECs and carbon offsets are sometimes discussed together, they are not the same thing.
Can RECs and Offsets Be Used Together?
Potentially, yes, but the building’s specific compliance strategy matters.
LL97 contains several deductions and alternative methods, and the rules can change as the City updates implementation requirements.
NYC Buildings currently identifies offsets, distributed energy resources, certain fuel cells, beneficial electrification, EV chargers, and other measures as potential deductions or alternatives depending on the building and applicable requirements.
However, owners should not assume that every available deduction can simply be stacked together without calculation or documentation.
A registered design professional may be required to prepare or attest to the applicable compliance documentation.
Why Timing Matters for LL97 Compliance
Timing is becoming increasingly important.
The first LL97 compliance period began with calendar year 2024 emissions, and the City is already managing later filing years. The 2026 Covered Buildings List identifies building-specific compliance pathways for covered properties.
At the same time, future emissions limits become more demanding.
This means a strategy that appears affordable today may not be sufficient several years from now.
A good LL97 strategy therefore looks beyond the current reporting year.
What Should NYC Building Owners Do?
- Confirm Your LL97 Compliance Pathway
Start by checking whether the property is subject to LL97 and which compliance pathway applies.
- Calculate Your Actual Emissions
Review energy consumption data for electricity, natural gas, steam, fuel oil, and other applicable sources.
- Identify the Compliance Gap
Determine whether the building is below or above its applicable emissions limit. If it is above the limit, quantify the gap rather than guessing how many credits you may need.
- Look at Building-Level Reductions
Review energy efficiency and decarbonization opportunities before relying heavily on credits.
- Evaluate Eligible Deductions
Once the building’s baseline and projected emissions are understood, evaluate qualifying RECs, AHRF offsets, distributed energy resources, beneficial electrification, and other applicable deductions.
- Work With Qualified Professionals
LL97 compliance involves technical calculations, documentation, reporting, and professional attestations. Working with an experienced LL97 compliance consultant can help owners understand the difference between a potentially useful credit and one that does not qualify under NYC rules.
So, Can RECs and Offsets Actually Help Your Building?
Yes, but they should be viewed as compliance tools, not a substitute for decarbonization.
Qualifying RECs can help address eligible electricity emissions. AHRF offsets can provide another limited compliance option while directing funding toward building decarbonization projects in New York City’s affordable housing sector. But both options have specific eligibility requirements and limitations.
The bigger opportunity is to reduce the building’s emissions at the source.
A practical LL97 strategy may combine energy efficiency, electrification, renewable energy, qualified deductions, and carefully selected credits. The right mix depends on the building’s current performance and future compliance requirements.
For NYC property owners, the goal should not simply be to find the cheapest credit.
The goal should be to create a compliance strategy that reduces today’s emissions, controls operating costs, and prepares the building for stricter requirements in the years ahead.
Final Takeaway
LL97 carbon credits can help, but they are not a magic solution.
RECs can potentially reduce eligible electricity-related emissions, while only specific NYC-approved offsets can currently be used for LL97 compliance. Generic carbon credits should not be assumed to qualify.
For many buildings, the best approach is to first understand the emissions profile, identify practical energy-saving opportunities, calculate the remaining compliance gap, and then determine whether eligible RECs or offsets make financial and regulatory sense.
As LL97 requirements become more stringent, building owners who plan early will have more options than those who wait until penalties become the only immediate concern.
The right question is not simply, “Can I buy carbon credits?”
It is: “What combination of building improvements and eligible compliance tools will give my property the most practical path to LL97 compliance?”
That is the question worth answering before making a major investment.
