There are some 2 million square feet of “green” roofs on federally owned buildings but GSA’s Public Buildings Service “does not have a comprehensive maintenance strategy in place to protect its investment” in them, an IG report has said.
Such roofs add layers atop a standard roof of waterproofing membrane, insulation, growth media, and vegetation ranging from herbs and grasses to trees. They are designed to capture storm water, reduce energy consumption, and improve acoustics, air quality, aesthetics, and biodiversity and habitat.
The report said that while such roofs are nearly twice as expensive to install than standard roofs and are slightly more expensive to maintain, their added longevity can produce long-run savings in addition to their other benefits. “However, failure to maintain green roofs will result in lost benefits, thereby negating the justification to install this premium roof type,” it said.
In a review covering sites making up two-fifths of the green roof inventory, auditors “found that in most cases PBS did not properly maintain the green roofs. We also found that PBS does not educate staff on maintenance requirements for green roofs and that PBS does not consider green roof maintenance costs when planning to install a green roof. PBS’s failure to maintain its green roof inventory has led to lost environmental benefits, wholesale green roof failures, and wasted taxpayer dollars.”