What does “green” really mean?
A sustainable roof must perform its primary purpose of protecting the building reliably and for the duration of its planned service life. The potential environmental burden created by premature roofing failure or its unplanned replacement is difficult to quantify. However, the means to prevent these issues, by sound design and consideration of demands placed on the roof, use of time-proven materials, proper installation and oversight, and adherence to planned care throughout the roof’s service life, are well understood. Green roofs can be only as green as the durability and performance of the underlying roof structure dictates. Downgrading the roof quality or placing primary importance on use of the roof surface for activities deemed sustainable, while overlooking the fundamental importance of the roof, can sacrifice roof performance and longevity. For these reasons, the emphasis of roof sustainability should be placed on the whole system.