Can it get any hotter in New York City?

NYC°CoolRoofs and Deutsche Bank teamed up this week to cool off a roof in the Bronx, and we tagged along.

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From black to white
From black to white

In New York City, and larger cities in general, summers for many have become an expensive and uncomfortable burden. Situated comfortably above Tom’s Restaurant of Seinfeld fame resides NASA’s Goddard Institute for Space Studies (GISS), one of the many organizations that contributed to PlaNYC, the city’s sustainability plan. They have a few answers to the growing heat problem in cities, which is also known as the ‘urban heat island’ effect, and which amplifies urban heat beyond even that caused by the background effect of climate change.

The NYC°CoolRoofs program was born to implement part of the solution suggested by GISS. You see the problem is us, and this time it’s not just CO2 emissions, it’s our predilection towards dark roofs and other surfaces that we inherited from Northern European influences. As a result the surface area of NYC has a low reflectivity of light radiation. Dark roofs love to soak up the sun, generating very high temperatures.

Albedo is the degree of light absorption and reflected radiation and it contributes to the ~7.2 degrees of additional heat generated during the summer months in the city. In recent years the additional heat generated has contributed to brownouts, deaths, and economic hardship during increasingly frequent heat waves. The conditions of heat waves, lingering high temperature over days or weeks, further amplify the heat island effects, as urban structures retain the heat and radiate it back out.

As a result of PlaNYC and Mayor Bloomberg’s NYC Services program, the 2008 construction codes were updated to require highly reflective roofs on new buildings. In April 2011 the city expanded the code to include retrofits of new buildings. So in time, all buildings in NYC will have reflective roofs.

The problem was what to do with existing buildings. The NYC°CoolRoofs program came out of that need. Wendy Dessy, the executive director, she describes the goal as simply turning roofs from black to white, but the amount of work required to do so is deceptive. The program exists as a partnership with the Department of Buildings, Community Environmental Center and Sustainable South Bronx, as well as corporate partners for funding, permits, volunteers and all the other minutia necessary to ensure that the program is successful. As of September 2013 they have coated 4,187,133 square feet of rooftops across 490 buildings, and engaged 5,095 volunteers in the work. Organizing all of the various vendors, talking with the many different building owners and finding the funding requires dedication.

Volunteers from Deutsche Bank painting
Volunteers from Deutsche Bank painting

The Cool Roof team makes the process for getting a cool roof simple. On staff is Loretta Tapia, who does site inspections and discusses with the building owner the options since a variety of choices are available from the basic paint, which comes at no cost to the owner, to higher end products where the owner pays the difference. The end result is the transformation from a black roof to a white roof and by doing so a reduction in heat absorption by the building. This translates to cost savings to the occupants of the building and a reduction in heat to the area surrounding the building.

On average a dark roof is 70-90 degrees hotter than the surrounding air temperature. With enough white roofs the USEPA reports that the urban heat island effect created by the abundance of dark surfaces in cities could be reversed if used on combination with other methods. This is especially true in Manhattan where 40% of the total area is rooftops. In a study by GISS, if light colored roofs replaced dark roofs in Mid-Manhattan West, the local air temperature would decrease by 1.4 degrees. If other strategies suggested such as green plantings, livings roofs, and light surfaces were adopted the city the results would be even more dramatic.

Painting roofs white is likely the cheapest strategy to cool neighborhoods. Planting trees, installing green roofs, and changing other surfaces around the city would require more significant investment. But it has been suggested by Brian Stone Jr., a professor of urban environmental planning at Georgia Institute of Technology, that this investment would yield long term economic savings in energy and pollution costs that would far exceed the investment.

I was fortunate to visit a project in the Bronx, an area which GISS identified as one of the hotter areas in NYC. The view from the rooftop gives a clear view of a sea of older housing stock with black roofs. On this particular day Deutsche Bank was the corporate partner. In addition to funding 50% of the cost to transform the roof, they gave their employees a chance to take the day off from banking. The event is part of Deutsche Bank’s corporate social responsibility philosophy of community development. About the partnership, Janet Wong, Vice President at Deutsche Bank Americas Foundation, said: “Deutsche Bank’s involvement in NYC CoolRoofs has been a terrific complement to its commitment to community development, sustainability and employee engagement. It has been especially meaningful to ‘connect the dots’ in neighborhoods in Harlem, Brooklyn and the Bronx where the Bank has been involved for many years. Many employee volunteers still talk about their coating days weeks and even months later and several come back year after year.”

There was plenty of excitement from volunteers on how nice it felt to do something tangible in the community. Everyone gives to charities but you seldom have a chance to see where the money is going. On the roof, they know that by the end of the day people will be spending less on electricity the next month, and for years to come.

By design the program will eliminate itself, and if the science is correct, result in a cooler, cleaner New York City. There are, according to the Dept. of Buildings and City Planning, more than 579 million square feet of roof surface in NYC, covering 226,525 buildings that would be prime candidates for white roof application. At the current rate of approximately 1.2 million square feet per year Cool Roofs still has a lot of work to do. (And could use plenty more partners.)

What is unique is that unlike other cool roofs programs being implemented across the United States NYC uses a substantial volunteer component. Many of the other cities are only now catching on to the volunteer possibilities. It is a simple job to paint a roof, especially with a team, and Sustainable South Bronx makes it even easier on the volunteers by preparing the roof and supplies so that all one has to do is apply the paint. Corporate partners like Deutsche Bank provide leads on buildings that could be painted. Individuals make the time to come up on the roof and do the job.

If you would like to do your part, but don’t happen to enjoy painting, then why not plant a tree with Million Trees NYC, another project that came out of PlaNYC that will eliminate itself with a job well done and bring us all some relief from the heat next summer.

(Photos: Nicholas MacDonald)