We went to check on one of the green roofs we installed last year in Park Slope. It looked good! Some of the edges were a little wind bare but for the most part the sedum were happy and growing.
We are Brooklyn green roof installers and it is really satisfying watching us spread a sea of green over the roof tops. It makes so much sense from an environmental point of view. If you do the math it is a no brainer. Lets say a green roof costs $10 to install vs. a tar roof that costs $3 and the green roof lasts four times as long. That means over the life of the two roofs the green roof costs $10 and the tar roof costs $12 since you have to replace it four times.
And lets say the green roof saves you $1 a year in energy savings since you need less heat in the winter and less cooling in the summer. Since a green roof lasts at least 40 years, you have a savings of $40.
At the end of the green roof you have spent $10 and saved $40. At the end of the tar roof you have spent $52!
I am using hypothetical numbers since each green roof is different but these numbers are pretty close to the average.
And this does not consider that a green roof is so much more valuable a product! In term of giving enjoyment it blows a tar roof away. In terms of ecology it is crucial in our world under siege.
Get a green roof installed! It is really a good thing to do on many levels.