Introduction - Problem definition

\label{introduction---problem-definition}
New York City in the plan called “80 x 50” has taken the challenge of reducing 80% of its carbon emissions, based on 2005 levels, by 2050. Since about two thirds of the city’s emissions come from energy used in buildings, it is fundamental for New York City and the Mayor Office of Sustainability (MOS) to evaluate and understand the energy consumption of the buildings in the city. As preliminary steps taken to assess the problem, the city passed two laws aimed at collecting granular and detailed data about the energy usage in some of its most significant emission sources: large buildings. These two laws are Local Law 84 and Local Law 87. [1]
Local Law 84 (LL84) requires that owners of buildings with a gross floor area larger than 50,000 ft2 report their energy and water consumption every year. The objective of reporting this information is to provide the city a better understanding of energy consumption patterns and of what drives the differences in energy usage among the different buildings. This practice of collecting information and comparing the energy performance of buildings is often referred to as benchmarking and has been adopted in similar ways for several other cities such as Chicago, Philadelphia, Seattle, San Francisco, Washington, DC.[1] Benchmarking, which is related to the concepts of efficiency and productivity analysis, is a way to achieve improvement through comparison with others who are the best within the area. In general, the concept is based on recognizing one’s shortcomings, acknowledging that others are doing better, and learning from them to implement in one’s case afterwards. [2]
To fully understand buildings’ energy consumption patterns, the city has also passed Local Law 87 (LL87) in 2009, which requires an audit of every building covered by the LL84 every decade. The audits began in 2013 and since then, every year about one-tenth of those buildings are audited. During the LL87 audits, the auditor also makes a list of retro-commissioning actions, which have the purpose of ensuring that the systems in place are operating as efficiently as they were designed to be.[1]
This project contributes to the final goal of reducing the carbon emissions that come from buildings in designing of a metric - similar to Energy Star Score - that can capture the particular characteristics of New York City buildings. This developed metric takes into account features of different building typologies and offers insights about the reasons behind the performance of each building, in addition to possible actions to improve that performance. This new calculated metric will be part of an Energy Scorecard along with several Energy consumption statistics. This Scorecard will be sent to each building owner (or manager) complying with LL84 as a way for the MOS to give something back to them in exchange for all the information they now have to provide to comply with LL84. Eventually also made available online.
The underlying motivation behind this project is that simply by better informing the building owners compliant to LL84 it is possible (and expected) that there will be some behavioral change towards a more efficient use of energy. That alone, i.e. sending a clear and informative Energy Scorecard to each of the building owners, may be found in the future to be an effective policy to significantly contribute for a more energy efficient and less carbon intensive NYC. Despite being an outcome that depends on many factors that are not in our control, that is the ultimate goal of building these models and developing this analysis.