i’ve been thinking a lot about this lately

Green roofs are good for everyone.

Community benefits
-Air quality - CO2 capture + particulate capture
-Capture storm water run-off
-Reduce heat island effect
-Potentially provide programmable green space (this is also a potential indiv benefit)
-Potentially provides habitat for birds, butterflies, etc.

Individual benefits
-Extend lifespan of the roof by at least 20 years
-Reduce heating/cooling costs - cooling by 95%, heating by 26%
-Reduced need for costly infrastructure like fancy HVACs and extra insulation
-External noise buffering
-Good public relations
-Tax breaks for LEED certification

10.76 sq ft of grass roof can remove between 0.2 kg of airborne particulates from the air every year. 16.15 sq ft of uncut grass, produces enough oxygen per year to supply 1 human with their yearly oxygen intake requirement.** using lightweight soil and herbaceous materials, very little alteration (if any) is needed for a standard roof. The primary cost is for the purchase of materials and installation, plus minimal maintenance - these costs are higher in the states because of the newness of the industry. However, with major businesses beginning to look for these resources, these costs are decreasing through economies of scale.

Enter Pathmark.

Each Pathmark receives a renovation or enlargement every five years. The stores are purposefully located in densely populated communities.* this means two things - first, it would take very little on their part to include greening in their normal business cycle, and, second, their greening would occur in the dense urban areas where it is most needed.

With an average of 52,800 sq ft per store, assuming a single floor (which is most common), 50 stores within 20 mi of zip code 10001 (manhattan), = 2,640,000sq ft of roof space.

2,640,000 sq ft of tarred or reflective roofs replaced with appropriate lightweight soil and herbaceous species means:

Community benefits
-At least 49070.63 kg or particulate matter removed from the air
-Enough oxygen for 163467.49 people per year
-70-90% reduction in storm water run-off

Individual benefits
Would be easier to calculate in real numbers if they told us more about their costs, but at a minimum:
-Sound reduction of 40 decibels for a 12 inch substrate
-Storm water capture and greywater recycling to reduce external input requirements (and the water bill)
-LEED points for categories: Reduced Site Disturbance, Protect or Restore Open Space, Landscape Design That Reduces Urban Heat Islands, Roof Storm Water Management, Water Efficient Landscaping, Innovative Wastewater Technologies, and Innovation in Design
-Tax incentives under New York State’s Green Building Tax Credit Program of up to $150/sq ft/credit (in other words, up to $27,72,000,000.)

That’s a lot of bang for very few bucks.

Write your elected officials. Write your unelected commercial suppliers. Wouldn’t it be neat to be able to see that much green space from the 7 train?

*stats are from http://sec.edgar-online.com/2000/09/28/17/0000947871-00-500009/Section8.asp
**stats are from http://www.greenroofs.org/index.php?option=com_content&task=view&id=26&Itemid=40

 ps the new formatting for wordpress makes me angry.