Here’s an update on NYC green roof policy incentives as discussed previously. According to an article in Greener Buildings, bill A 11226 passed the state assembly on June 23rd. The senate had previously passed the bill on June 11th. For buildings that green at least half of the roof surface, they may receive a one-time tax credit of $4.50 per square foot (up to $100,000) of green roof.

So how does $4.50 per square foot compare with the cost of a green roof? In our study on the costs and benefits of extensive green roof systems, which included costs to install the conventional components in addition to the green components, we found that 4 inch systems were on average $22 per square foot. An intensive system would certainly cost more, and there are certainly variations in this price. Assuming this price per square foot, the incentive covers about 20% of the cost. By reducing the upfront cost with an incentive, the time required for a return on investment (ROI) is reduced considerably. Considering only energy savings and a reduced stormwater fee, typically the average green roof takes 20 years before ROI can be reached. With the additional incentive, this can reduce the time required for an average roof to 12 years. Not a bad deal.