New York City has adopted a data-driven approachvi to deliver its ‘30x17 target’ (30% GHG emissions reduction below 2005 levels by 2017). The city uses its benchmark results and other data sources to monitor building performance over time and prioritize energy efficiency projects. The city has also implemented its principal energy efficiency legislative package - the ‘Greener, Greater Buildings Plan’vii (2009), expanded by ‘One City: Built to Last’viii (2014) – requiring energy audits and cost-effective retrofit measures as well as promoting clean energy. The city evaluates the energy performance results regularly through extensive monitoring and year-to-year data analyses against benchmark baseline scores. These allow the city to identify the impact that different factors, such as energy efficiency investments, smart building management and occupant behaviour have on energy use.



Local Law 84 of 2009 (part of the Greener, Greater Buildings Plan) requires reporting of benchmarking results for all buildings of at least 10,000 gross square feet that are owned by the city or for which the city pays the annual energy bills, as well as for private buildings over 25,000 gross square feet (around 2,300 square meters) from 2014. As of August 2015, around 11,800 facilities had been benchmarked,ix with those buildings identified as having the greatest opportunity for energy savings prioritised for retrofitting. To date, the city’s building retrofit programme has resulted in over 190 energy efficiency projects, with annual energy cost reductions of around $10.5 million. The ‘One City: Built to Last’ programme takes this a stage further by targeting every government building requiring significant energy upgrades.


Reasons for success

The success of NYC’s data approach is based on the comprehensive scope of the exercise, targeting a large number of buildings to create an extensive database allowing for more robust benchmarking. Coupling the data-gathering with targeted energy audits also helps to diagnose specific problems and ensure more targeted retrofits.


When/why a city might apply an approach like this

Cities in general should adopt the comprehensive energy mapping and data-driven approach as a critical first step to improving energy efficiency in buildings. The approach provides a critical starting point and allows monitoring over time to help maximise energy efficiency and cost-effectiveness, ensure that retrofits are targeted most effectively and that energy efficiency investments achieve maximum value. 


C40 Good Practice Guides

C40's Good Practice Guides offer mayors and urban policymakers roadmaps for tackling climate change, reducing climate risk and encouraging sustainable urban development. With 100 case studies taken from cities of every size, geography and stage of development around the world, the Good Practice Guides provide tangible examples of climate solutions that other cities can learn from. 

The Municipal Building Efficiency Good Practice Guide is available for download here.  The full collection of C40 Good Practice Guides is available for download here.  

All references can be found in the full guide.