The Rise of Green Buildings

The map above displays some of the U.S. cities with the largest number of LEED-certified building projects, with New York at the top of the list with 678. Washington D.C. holds the title of the first LEED Platinum city, with the largest per capita square feet of green building space. While there are many other building rating systems (which will be detailed below), LEED is the most widely pursued in the US. Click on the location markers to read more about the number of LEED-certified buildings in each city.

This layer was taken from the open source database on ArcGIS online that summarizes the USA property energy use by major cities in 2011. EUI (energy use intensity), measured as thermal units per square foot, is used as the primary metric for this and all following maps. Since this EUI is not weather normalized, it is evident that areas in northern half of the country have higher energy use due to year-round temperature extremes; biting winters lead to higher heating demand while sweltering summers lead to high air conditioning demand. New York is shown to have a remarkably high EUI, which along with high flood vulnerabilities if the current rate of sea level rise around the city continues, means that there is a serious need to build more resilient and energy-efficient building infrastructure.

As seen through maps published by the BCAP, New York has relatively stringent building codes, adopting standards that meet or exceed those published by the 2015 IECC. Through the Greener Greater Buildings Plan (GGBP), a series of 4 local laws passed in 2009, New York City has mandated that buildings with more than 50,000 square feet report their building energy and water use as well as benchmark their performance on an annual basis.

According to an inventory of all NYC Greenhouse Gas Emissions compiled by the city government 2010, buildings caused 75% of city-wide carbon emissions. While there are over a million buildings in the city, only 15,000 properties (1.5% of all buildings) contributed to 45% of the city-wide energy consumption. The massive use of energy not only stems from the high energy demands of everyday operations, but from fundamental inefficiencies in HVAC systems across the city. Another piece of rather unprecedented legislation is the city's "80-by-50" law, which pledges an aggressive carbon reduction goal of 80% by the year 2050. There are several milestones between now and 2050 to break down this ambitious target, with building emissions required to reduce by 40% before the year 2030.

While other cities like San Francisco and Washington D.C. have passed similarly ambitious targets, NYC legislation promises a fine for every ton of carbon in excess of the emission target, the first to "attach a dollar value to these disclosure figures" (Capps, 2019). The associated penalties give this pledge a lot more teeth, and are forcing building owners to act fast before 2030. Developers not only have the responsibility of ensuring compliance of all new construction projects to green building standards, but to conduct retrofits on aged existing buildings that are not performing to modern energy and water efficiency standards.

The map above, which plotted weather normalized source EUI data from 2017 for over 20,000 buildings, had publicly-accessible and downloadable CSV data. Around 2/3 of these properties represented multifamily residential units, while the rest comprised of offices, K-12 schools, hotels, retail stores, and more. Since I wanted an easier-to-read map that also categorized energy use intensity by zip code, I decided to download this data and manipulate it to create my own polygon feature layer in ArcMap. In the metadata, all of the buildings had recorded zip codes, which was very helpful for averaging the EUI of all of the buildings within each zip code to visualize a representative energy use intensity for that particular zip code. My method was as follows:

1) Download the CSV data from here:  https://energy.cusp.nyu.edu/#/ 

2) Organize the data by zip code

3) Manually find the average EUI for each zip code by averaging the EUI of all of the buildings within that zip code

4) Download a simple New York City zip code shapefile and open it in ArcMaps

5) Add a new field into the attribute table and input all of the EUI averages for each zip code

6) Export as a new zipped shapefile and add as a new hosted feature layer to ArcGIS Online for use in multiple maps

Based on the map generated above, which plots NYC green building projects on top of zip codes that are color-coded by EUI data, we can see that there is the opportunity for more sustainable building projects in lower Brooklyn, Staten Island, and the Bronx, where the average building EUI is quite high. Within Manhattan, there is also notably high EUI in the East Village, Upper West Side, and East Harlem. While some zip codes had considerably less data than others, this might be a compelling way of exploring new sites in need of energy retrofits for compliance to the upcoming 2030 emissions report. There is, however, a lot to be said of the distribution of current green building projects relative to the housing affordability or wealth indexes of certain zip codes. The dense spattering of green buildings in the heart of Manhattan might suggest, however, that sustainable new construction and retrofits are very costly and cannot be fulfilled by projects in less affluent zip codes.

As depicted by the two maps above, a significant amount of green building projects can be found in the more affluent areas of NYC. The first map, which shows the prevalence of sustainable residential building projects in census tracts with higher median incomes (darker green-shaded areas), suggests that residents with higher incomes can afford to rent or own homes in buildings that pursue sustainability ratings. The second map, which plots the Passive House projects on top of NYC counties that are color-coded by housing affordability index, also shows that there are more existing Passive House buildings in areas that are less affordable (darker red-shaded areas). Passive House certification is an energy-focused green building rating system touted in the industry for increasing building energy efficiency by 60% while LEED certification boosts building energy efficiency by only 20%. This is likely due to the fact that LEED is a more holistic checklist that considers characteristics like water efficiency and indoor environments while Passive House is a more performance-based standard.

The takeaway of the maps above are that sustainable buildings may be prohibitive for less affluent neighborhoods or communities financing other obligations in large cities, especially when there is sweeping legislation that will impose fines for noncompliance in the not-so-distant future. While it is certainly a great incentive to begin taking building energy and water-use efficiency more seriously, there should also be conversations about making the retrofit or sustainable design process affordable to all communities. For instance, mandated greener state-wide building codes will lead contractors to normalize prices on sustainable building materials that would otherwise be sold at a premium. Cost-saving also happens throughout the lifespan of a building with reduced heating and cooling needs, which should be maximized in order to justify the upfront fees for Green Building Council's LEED or Passive House certifications (or any other rating system) and any extra effort required to design a more energy and water-efficient building.

The layer above is a point feature layer generated in ArcGIS Online using private sector energy and water data reported to the NYC Mayor's Office of Sustainability for the 2017 calendar year. The entire dataset had more than 30,000 reported buildings, so I decided to focus on the buildings with the highest EUIs. I filtered out the top 68 buildings, which all had EUIs larger than 1,000 kBtu/ft², and generated the coordinates to each listed address with the help of Google Maps. I added these coordinates as a CSV file to a point feature layer on ArcGIS Online and generated these plots. The distribution of these points suggest the concentration of the most energy-intensive buildings, and could create a compelling image with the inclusion of all 34,355 building that reported energy and water-use data.

Time and capacity constraints prevented me from performing a similar analysis of water-use data, which is also a key feature that sustainable building certifications consider. In the process of completing this project, I was able to find one published by an Advanced GIS student that plotted completed projects by the New York City Energy Efficiency Corporation along NYC flood zones. I took inspiration from this project to conduct a similar analysis of high site EUI buildings overlaid on energy-intense NYC zip codes.

This project was made possible by the support of professors Nicole Wagner and Carr Everbach through the Spring 2020 Capstone Seminar in Environmental Studies: GIS (ENVS091).