City Needs to Nourish Green Roofs on Co-ops and Condos

Scott Stringer is city comptroller. Danielle Spiegel-Feld is executive director of the Guarini Center on Environmental, Energy and Land of Use Law at New York University School of Law. A longer version of this article appeared in Crain’s. 

By transforming barren roofs into verdant spaces, we can improve water quality, slash energy use, foster biodiversity, and provide more enjoyable space. The canopy of plants on green roofs drink up stormwater, reducing runoff by more than 50 percent. Green roofs also insulate, drastically cutting the expense and emissions from heating and cooling. 

Yet New York City has done an exceedingly poor job of assisting property owners in greening their rooftops. A centerpiece of the city's efforts – a property-tax abatement – has failed. It can defray the cost of installation by as much as $100,000, but only seven roofs have been granted the abatement in the program's nine years. As a result, green roofs cover only 1 in 1,000 buildings across the five boroughs. With the incentive set to expire next year, the city seems poised to abandon it. But we shouldn't give up now. 

The program offers a meager $5.23 abatement for each square foot of vegetation, about half the minimum that experts say would spur property owners to act. Without adequate compensation, few co-op or condo boards or other building owners have applied for the credit, so the city has spent nowhere near the $1 million per year Albany authorized. 

A study commissioned by the Washington state Department of Energy and Environment found that every dollar invested in green roofs generated $2 in benefits by mitigating stormwater runoff and providing green space. That's why cities, including San Francisco, Philadelphia and Toronto, have implemented bold policies to promote green roofs. 

It's time for New York to catch up. The program should be restructured to provide a more targeted tax credit to a rotating group of neighborhoods that struggle with regular sewer overflows or a lack of green space. And we should decrease or even eliminate the abatement offered to properties elsewhere. Rather than having an incentive available everywhere – but not worth enough to trigger action anywhere – we could offer a substantial inducement to effect change in the areas that need it most. 

By focusing on a few specific neighborhoods each year, we can raise the per-square-foot value of the abatement to make it more appealing to building owners. This way, the city can increase the program's impact without having to increase its funding. 

Tailoring a credit to match community needs isn't unprecedented. Officials in Washington, D.C., started to vary the size of incentive payments for green roofs based on location several years ago. If they can do it, so can we. The city’s 62 square miles of rooftops comprise an asset that's too valuable to waste.