DEC 02

New York City's largest green roof sits atop the U.S. Postal Service's Morgan Processing and Distribution facility in midtown Manhattan.  On this roof resides 2.5 acres of dense vegetation that two years after its installation have made a major impact on the building and the city.

The green roof, which is one of the largest in the country, was completed in December 2008 and since then has really become living proof of the power of green roofs.  The roof has has reduced the building's storm water runoff by 75 percent in the summer and 40 percent in the winter.  The U.S. Postal Service says the roof's ability to cool the building in the summer and insulate it in the winter saves about $30,000 a year in energy costs.

While green roofs are more expensive than traditional roofs initially, they last 50 years -- more than twice as long as a traditional roof and they quickly lead to savings in storm water management, heating and cooling, cleaning the air and costs related to the urban heat island effect.

Toronto, the first city to mandate green roofs on new construction just this past year, has conducted studies that concluded that if 75 percent of the city's roofs were greened, the city would save $37 million a year.  Urban heat island effects could be reduced by as much as 2 degrees Celsius.  You can read more about the Toronto bylaw here.

via Yale e360

Comments (11)

Subscribe to this comment's feed

...
written by Susan, December 02, 2010

New York would be a great place to have mandated green roofs like Toronto. But this is a start! Impressive numbers.

• 
• +1
• 
• 

rain water sequestering
written by Mike, December 02, 2010

I'm curious how this would be played out around the country. I've heard of several locals threatening to fine for unauthorized rain water sequestering. Usually in the case of homeowners capturing the rain from the roof to water garden, plants etc.

• 
• +0
• 
• 

Disease vector, Low-rated comment [Show]

Are you serious
written by Dave, December 03, 2010

@Carol it's been a while since I've been prompted to respond to an inflammatory post and yet here I am. How can you call rain water stolen? That is absolutely an abuse of the term and reflects an attitude that will inevitably result in conflict and we need more conflict right? What about the water that actually hits the ground and is absorbed or sequestered in an aquifer, is that theft? Invasive weed species? Malaria? Pesticides? The roofs of high rise buildings are so often concrete wastelands and while there may in future be an opportunity to generate electricity from that space, creating more green sounds like a step in the right direction to me.

• 
• +8
• 
• 

To Carol
written by Taith, December 03, 2010

In some urban area's doing anything to get the water stored away other than the sewer system that can't handle it would be a blessing.

Every time it rains heavily in Hoboken during high tide the southwest part of town has flooding problems. I'm talking water that can stall out cars and ruin the carpet in your car. I'm talking flooded basements.

In some urban environments there is not enough ground that has not been covered with concrete and aspalt for the water to go anywhere useful.

Can you quote any sources for your weed or mosquito claim?

• 
• +7
• 
• 

weeds and mosquitos?
written by John, December 04, 2010

I think it's silly to suggest that green roofs would be a haven for invasive species. If a green roof provides habitat for invasive species, then it can also provide habitat for native species. I'm sure no one would knowingly plant weeds on their green roof, and given that a roof is a very discrete area, I would think it easy enough to weed without using pesticides. As for mosquitos, why would there be enough standing water on a green roof to provide breeding habitat for them?

• 
• +2
• 
• 

...
written by Ray @ Diy Solar Panels, December 05, 2010

Is there any info on how much more green roofs cost becuase if the savings are 30K per year in the long run may be they are lot cheaper like every other green technology

• 
• +0
• 
• 

...
written by net97surferx, December 09, 2010

The article says it saves about $30K a year as compared to standard roofing. I wonder though... how much did this 'green roof' cost to prepare/install to handle the load of ground/water/plants as compared to a standard installation AND how much more does it cost per year to maintain and upkeep that 'lawn' / garden for 50 years as compared to just letting a standard roof 'get old' over the same period of time?

I mean, I like the idea of 'greening up' a city and using rooftops for a place to have 'real living stuff' in the concrete jungle... but, sometimes the story tends to gloss over the specifics to make the results sound a bit of 'too good to be true' sometimes.

• 
• +2
• 
• 

Want to see green everywhere
written by Jessica Janes, March 17, 2011

If big cities can do this, than everyone should be able to add green roofs. Easier on the eyes and lungs.

• 
• +0
• 
• 

...
written by Dave@topdiysolarpanels, February 25, 2012

They build a similar roof in Malaysia for the largest manufacturer of milk over there

• 
• +0
• 
• 

...
written by gurjeet, October 12, 2012

how much more does it cost per year to maintain and upkeep that 'lawn' / garden for 50 years as compared to just letting a standard roof 'get old' over the same period of time?

• 
• +0
• 
• 

Name

Email

Website

Title

Comment

smaller | bigger

Subscribe via email (registered users only)

Write the displayed characters

Add Comment