Today, Mayor Zohran Kwame Mamdani announced significant progress in cutting greenhouse gas emissions from buildings across New York City, including 95% of large, privately owned buildings meeting emissions limits under Local Law 97, nearly 700 properties receiving support through the relaunched NYC Accelerator and major new investments in clean energy and sustainable construction across the city's public buildings and affordable housing.
Buildings account for two-thirds of New York City's greenhouse gas (GHG) emissions, making them central to the fight against climate change. As New York marks Climate Week, the progress announced today demonstrates how the Mamdani administration is using every tool available - from enforcing emissions standards to expanding solar power, electrifying buildings and investing in climate-resilient affordable housing - to build a cleaner, healthier and more sustainable city.
"Climate change is not a problem for someone else to solve someday. It is here in New York City, and our buildings are where we both have a responsibility and an enormous opportunity to act," said Mayor Mamdani. "We are cutting emissions in the buildings where New Yorkers live, work and learn, while making those buildings healthier and more resilient. From enforcing Local Law 97 to putting solar panels on schools and installing heat pumps in affordable housing, we are proving that climate action can improve New Yorkers' lives today while building a city that is ready for tomorrow."
"Improving building efficiency is one of the best ways that we can make our city greener than it is today and tackle the broader climate crisis. We're bringing a whole-of-government approach to sustainability, ensuring our City assets are as green as possible while continuing to regulate building emissions and help even more people live in sustainable, transit-rich communities," said Leila Bozorg, Deputy Mayor for Housing and Planning.
"Our buildings are what make our skyline iconic, but they're also our city's greatest contributor of greenhouse emissions. Every milestone in emission reduction is another opportunity for us to challenge this city to do better and go farther to protect New Yorkers from the dangers of pollution and climate change. We look forward to working across agencies and alongside building owners citywide to champion an ever-greener New York City," said Julia Kerson, Deputy Mayor for Operations.
"Cleaner buildings mean healthier New Yorkers," said New York City Chief Climate Officer Louise Yeung. "The progress we're seeing across the city shows what's possible when we bring together the resources, partnerships, and practical solutions needed to improve the buildings where New Yorkers live, work, and learn in communities across all five boroughs."
Lower Emissions at Privately Owned Buildings
The Department of Buildings (DOB) recently released new data showing widespread compliance with Local Law 97. About 95% of the approximately 20,000 private properties covered by the law filed a compliance report with DOB, and about 95% of the buildings demonstrating compliance through improved building efficiency are meeting their emissions targets during the first year of enforcement.
Building owners can also demonstrate compliance with Local Law 97 by purchasing offset certificates through the City's Affordable Housing Reinvestment Fund. The fund has raised approximately $1.7 million to date to support decarbonization projects at affordable housing buildings across New York City.
The Mamdani administration has also relaunched NYC Accelerator, a free, concierge-style service that helps building owners and property managers plan, finance and complete decarbonization projects. Since its relaunch in April, NYC Accelerator has assisted nearly 700 properties, including 448 now using the online Momentum tool for compliance calculations, project scoping and retrofit management.
The Mayor's Office of Climate and Environmental Justice (MOCEJ) has also launched the next phase of the NYC Carbon Challenge, a partnership with 127 private and nonprofit organizations working together to develop and share tools for cleaner, more efficient buildings. Participating institutions represent nearly 600 million square feet of real estate and have collectively kept nearly 1 million metric tons of carbon emissions out of the atmosphere.
City-Owned Buildings Lead the Way on Sustainability
The City is also continuing to reduce GHG emissions from its own operations, which have already been reduced by 31% from 2006 to 2025 - reaching the lowest level in 20 years.
Over the past 12 years, the City has implemented more than 17,800 energy conservation measures across 2,500 facilities, reducing approximately 460,000 metric tons of carbon dioxide - the equivalent of taking 100,000 cars off the road.
The City has installed nearly 36 megawatts (MW) of solar power across 222 facilities, including 29 MW at 138 schools. An additional 78 school solar installations are currently in progress through the NYC Solar Schools Program.
Earlier this year, New York City Public Schools (NYCPS) and the Department of Citywide Administrative Services (DCAS) completed the City's first solar canopy electric vehicle charging installation at a public school, at The Michael J. Petrides School on Staten Island. In 2025, NYCPS also completed the City's first boiler conversion to 100% biofuel at Edward R. Murrow High School in Brooklyn.
Public schools are also serving as living laboratories for climate education and green career pathways. Through the NYC Solar Schools program, DCAS and NYCPS have trained more than 1,600 teachers and 19,000 students as of 2026, in partnership with Solar One.
The City is also using new procurement tools to accelerate clean-energy projects. Earlier this year, DCAS registered a contract for solar photovoltaic installations through "design-build," which combines design and construction into a single procurement and can streamline project delivery. The contract is the City's third design-build contract.
In partnership with Governor Hochul and the Metropolitan Transportation Authority (MTA), the Mamdani administration is also exploring a landmark thermal energy network study as part of the Chambers Street J/Z station renewal project. The proposed system would recycle excess heat to warm nearby municipal buildings during the winter and could become the first thermal energy network in a U.S. transit system.
MOCEJ has also partnered with the NYC Office of Technology and Innovation (OTI) to test zero-emission construction equipment at City sites, including Parks operations in the Rockaways and a Department of Sanitation facility on Staten Island.
In February, the Mamdani administration, led by the Department of Design and Construction (DDC), opened the new Shirley Chisholm Recreational Center, New York City's first public building to meet LEED v4 Platinum standards for environmental sustainability.
Advancing Sustainability in Affordable Housing
The Mamdani administration is also improving energy efficiency and cutting emissions in the affordable housing New York City owns and finances.
The New York City Housing Authority (NYCHA) released its Sustainability Agenda in April, with a goal of installing clean, electric heating and cooling systems in 20,000 apartments over the next five years, among other initiatives.
Earlier this week, NYCHA unveiled a model sustainability apartment at the Brooklyn Navy Yard showcasing the heat pumps, induction stove and far-infrared heating panels being installed as NYCHA and its partners renovate properties across the city.
NYCHA is also pursuing additional decarbonization efforts through the electrification of domestic water heating systems, installation of energy-efficient windows, building-envelope insulation improvements and a commitment to install 10,000 induction stoves across its portfolio. Together with plans to install 30 megawatts of solar energy and 150 electric vehicle charging stations across NYCHA campuses, these investments will improve resident comfort and well-being while reducing greenhouse gas emissions and energy use.
The Department of Housing Preservation and Development (HPD) is advancing sustainability through the affordable housing it supports, including 60 affordable housing projects built to "Passive House" sustainability standards and solar panels generating 17 MW of energy atop affordable housing developments.
HPD has also allocated funding for nearly 2,800 households in 70 existing buildings to install heat pumps and updated its New Construction Design Guidelines to ensure that projects supported by the City minimize climate impacts while protecting New Yorkers from increasing climate risk.
"Recognizing that the 1.1 million buildings across the five boroughs account for the majority of harmful greenhouse gas emissions in our city, city agencies are stepping up to tackle the issue head on," said Buildings Commissioner Ahmed Tigani. "Through our smart implementation of Local Law 97 carbon emission limits, DOB and our agency partners are helping tens of thousands of the city's largest buildings get on a manageable compliance pathway to net-zero emissions by 2050. We are proud of the collaboration with our agency partners, grateful for owners who are making the investments and implementing changes needed to meet this moment and all relevant stakeholders working to keep New York City a leader in the field of building sustainability."
"DCAS and the City of New York are at the forefront of efforts to reduce building emissions as we mark tremendous progress and see our lowest carbon footprint in 20 years," said DCAS Commissioner Yume Kitasei. "Climate week is a time to recommit ourselves to carbon reduction efforts; under this administration, we are tackling climate change head-on through our investment in solar panels, critical retrofits to aging building systems and innovative solutions to modern energy needs."
"Sustainability is a key component in our work to preserve our aging housing stock and our recent 2026 Sustainability Agenda is the roadmap guiding that work," said NYCHA Chief Executive Officer Lisa Bova-Hiatt. "Decarbonizing public housing means healthier, more comfortable, and more resilient homes for residents, and lower energy costs over the long term. By working alongside city agencies, partners, and residents, we are advancing solar, heating, and resiliency projects that will make our portfolio more efficient and better prepared for the impacts of climate change. We are appreciative of the Mamdani administration's continued partnership and commitment to ensuring that public housing residents are at the center of the city's climate progress."
"As the City's primary capital design and construction project manager, DDC builds many of the civic facilities used by New Yorkers every day and we are using every tool in our toolbox to aggressively lower our carbon footprint," said NYC Department of Design and Construction Commissioner (DDC) Paul A. Ochoa. "By collaborating with sister agencies and world-class design and construction professionals, DDC achieves performance standards that far exceed private building industry averages. We are driving down carbon emissions by slashing energy use, eliminating on-site air pollution and by integrating clean solar energy and green infrastructure in our public buildings and Envision standards in our horizontal projects. In the face of increasingly severe weather, these resilient design standards are more urgent than ever."
"As flood levels rise and extreme weather events become more commonplace, it is more important than ever that we focus on the resiliency of our housing," said HPD Commissioner Dina Levy. "Through our climate-focused design guidelines, sustainability training and resources, and initiatives such as the NYC Accelerator program, HPD is working to protect New Yorkers from climate threats while improving their quality of life."
"Every school we build is an opportunity to create a healthier, more sustainable learning environment for our students and the communities they call home," said School Construction Authority (SCA) President and Chief Executive Officer Celeste A. Ramirez. "From the geothermal system being incorporated into the new school we're building at the former St. John Villa in Staten Island to the bio-solar panels on the roof of K004, which opened this year in Brooklyn, we are making sustainability part of how we build schools for the future. We look forward to strengthening our collaboration with the Department of Buildings to expand the use of photovoltaic panels in new school buildings. This Climate Week, we are proud to reaffirm our commitment to developing green, accessible schools that reduce our environmental impact, strengthen our communities and create learning environments that can serve every child."
"Climate Week brings together the world's leading minds on the climate crisis, and it's also a chance to recognize the real progress we've made cutting carbon emissions right here in the five boroughs," said New York City Economic Development Corporation (NYCEDC) President & CEO Anthony Shorris. "The results are clear, and through efforts like the NYC Mass Timber Studio, the City is investing in the implementation pathways needed to efficiently and sustainably deliver homes for New Yorkers, while creating a more resilient, low carbon city for all."
"New York City is proving that climate action can deliver affordable, healthy and resilient buildings for all New Yorkers," said Urban Green Council CEO Chris Halfnight. "Local Law 97's strong start is a milestone achievement - with 95% of reporting buildings meeting their limits - and we look forward to building on that momentum with Mayor Mamdani and the dedicated teams at DOB and MOCEJ."
"The reality is that the buildings that define our iconic city also create two thirds of our climate pollution. Thankfully, New York City's Local Law 97 and the city's cutting-edge retrofits for schools, NYCHA, and HPD multi-family buildings are helping to address the problem," said Samantha Wilt, New York Policy Director, Climate & Energy at the Natural Resources Defense Council (NRDC). "Climate action delivers cleaner air inside and outside, better buildings for residents, and a stronger, more resilient New York City for all of us."
"While the purpose of Local Law 97 is simple - to lower greenhouse gas emissions from our buildings - its implementation is complex. But with 95% of large privately owned buildings under the law's performance pathway meeting their limits, it is clear that New York City is up to the task. We applaud Mayor Mamdani for his commitment to reducing toxic air pollution and tackling the ongoing threat of climate change, as well as the thousands of building owners meeting this challenge head on," said Alia Soomro, Deputy Director for New York City Policy, New York League of Conservation Voters (NYLCV).
"We applaud the Mamdani administration for the City's continued progress on compliance with Local Law 97 of 2019, with 95 percent of large, privately-owned buildings investing to reduce emissions or purchasing offset certificates - the latter of which raised approximately $1.7 million for decarbonizing affordable housing - during the first year of enforcement," said Lonnie J. Portis, Director of Policy and Legislative Affairs at WE ACT for Environmental Justice. "We look forward to seeing similar progress with the Affordable Housing Reinvestment Fund projects, so those most impacted by these admissions can also participate in a just transition away from fossil fuels."
"The work that the Department of Buildings has done to support building owners comply with Local Law 97 cannot be praised enough," said Rob Freudenberg, Vice President of Energy and Environment at Regional Plan Association. "No other city in the country is undertaking an effort to improve the quality of life and performance of our buildings on the scale of New York City, and the city is showing that living sustainably is possible."
