New York - One City: Built to Last, and the Buildings Technical Working Group


One City aims to overcome historic under-investment in the City’s public buildings and the lack of private sector investments in energy efficiency. One City targets major barriers such as a lack of information transparency about private building energy use, limited resources for investment, and mistrust in a fragmented market for energy efficiency.

The TWG is seeking to overcome the high cost of deep building retrofits and the uncertainty of planning for 2050 due to unforeseen long-term changes to technology, power supply, and demand for energy. The TWG is supported by a technical study that assesses multiple pathways for GHG reductions in buildings and their associated costs.


The City will make direct investments in its building stock to ensure public buildings are models for energy efficiency and sustainability.

The City will also assist private sector actors in making necessary building upgrades through the Retrofit Accelerator by focusing on using information collected about its building stock to simplify the process of completing retrofits and removing barriers to action.

The City will also require all buildings over 25,000 square feet (2322.58 square meters) to measure energy and water use and complete energy assessments, and require large building operators to be trained in energy efficiency best practices. 

Through the TWG, the City is also utilizing this data to develop GHG reduction strategies across nearly 20 building typologies to map out several pathways to deep carbon reductions. 


Projected Outcomes


The overarching climate change goal of this project is to put NYC on the pathway to 80x50, the goal that the United Nations says is necessary for developed countries to avoid the most disastrous impacts of climate change.  Another major goal of One City is to achieve market transformation in the building industry over the next decade by stimulating a thriving private market for renewable energy and energy efficiency.

The programs and initiatives included in One City are expected to reduce NYC’s GHG emissions by approximately 3.4 million metric tons annually by 2025. The TWG will develop additional policies, programs, and mandates that will ensure that NYC is on the pathway towards 80x50. 

One City and the TWG are integrating climate resiliency into programs and initiatives. The City has committed to expanding the NYC CoolRoofs program to help reduce the urban heat island effect, and the NYC Retrofit Accelerator will target private sector buildings located in the floodplain for upgrades that will also provide resiliency benefits.

The programs and initiatives included One City are expected to reduce energy use by 8.45 MMBtu annually by 2025 and water use in buildings by at least 3.73 million gallons (14.12 million liters) annually by 2025.

One City also sets two 10-year targets for solar power by 2025: 100MW capacity on City buildings and 250MW capacity on private buildings.

One City will reduce energy costs by $1.4 billion a year, $8.5 billion in cumulative savings by 2025. As low-income residents pay a disproportionate share of income on utility costs, One City includes a number of initiatives to increase energy efficiency in affordable housing.

The initiatives in One City are expected to create 3,500 jobs, train 7,000 building staff to upgrade their skills, and catalyse a market of energy efficient products and services.



Included in these initiatives is the expansion of existing local laws requiring large buildings (over 50,000 square feet) to complete energy and water benchmarking, energy audits, retro-commissioning, lighting upgrades, and sub-metering to cover mid-sized buildings (over 25,000 square feet) as well.  It also includes creation of an innovative new program called the Retrofit Accelerator, which will utilize the information collected through these local laws to conduct data-driven outreach and provide assistance to help private building owners with the greatest opportunity for efficiency investments to complete energy and water retrofits in their buildings.  These and other innovative programs included in the plan will reduce building-based emissions 30% by 2025.

The Buildings Technical Working Group (TWG) was convened following the release of One City to determine the longer-term strategies needed within the buildings sector to place the City’s building stock on the pathway to a citywide 80% reduction in GHG emissions from 2005 levels by 2050 (80x50).