Posted 6/1/2009 12:00 am
Updated 2 years ago
Although the Arkansas Department of Environmental Quality's headquarters received the Gold Leadership in Energy & Environmental Design rating from the U.S. Green Building Council in 2007, the six-story building could have been even greener.
The ADEQ had planned to place a rooftop garden on the North Little Rock building, which cost more than $22 million. The ADEQ had hired Mesa Landscape Architects Inc. of Little Rock to design the rooftop garden, which could have lowered the temperature of the roof by 40 to 60 degrees, saving on cooling costs and extending the life of the roof.
But the ADEQ decided to scrap its plans for the rooftop garden. ADEQ officials thought they didn't have the employees for the maintenance of the garden, which would have been planted directly on the building's roof.
While other cities have seen an increase in garden roofs over the past decade, Arkansas building owners have been slow to add the feature. But that could change if more of the developers who express an interest actually follow through.
Mesa Landscape owner Mark Robertson said he designed a rooftop terrace and garden, costing about $100,000, for a downtown Little Rock project. But the project was shelved in the fall. Robertson declined to identify the project.
He also is planning to bid for the job of designing a green roof for the Little Rock Zoo's new Laura P. Nichols Penguin Pointe exhibit. Robertson said he hoped that the project would be open for bid soon.
Little Rock Zoo spokeswoman Susan Altrui said last week that the zoo was moving forward with the green roof.
"We are waiting on the city to refinance the 1998 bond fund," she said. "When that happens, that will give us the money we need to complete the fundraising for the penguin exhibit." Altrui said she expected that to happen in the next two months.
Altrui said the zoo wanted the green roof because it was always "looking for ways to encourage conservation and to practice what we preach."
The construction cost is projected at about $2.2 million, and the exhibit will feature eight penguins.
Robertson said green roofs had "a lot of potential" in Arkansas. A green roof "helps in a lot of different ways," Robertson said. "We need to be seeing more of them. ... Europe has been doing green roofs for decades."
Still, there aren't many rooftop gardens in Arkansas.
Steve Wyman, the manager of Good Earth Garden Center & Nurseries
in Little Rock, said his company maintains the green roof at the Clinton Presidential Library, which features native plants and grasses. The University of Arkansas campus in Fayetteville also has two green roofs.
"I'm not really sure why it's not as popular here as it is in other parts of the country," said Carl Smith, an assistant professor at the Fay Jones School of Architecture at the University of Arkansas.
The ADEQ didn't go forward with its garden roof because "officials at the time determined that the agency didn't have the manpower for the ongoing maintenance of that," ADEQ spokesman Aaron Sadler said. He also said startup costs were an issue.
Sadler said he didn't know what the costs would have been to maintain the roof.
The cost to install a rooftop garden varies, but it can add $10 a SF - or more - to the roof. Robertson said he didn't remember what it would have cost the ADEQ, but figured it was in the $20- to $30-SF range.
Robertson said that he was disappointed when he learned that the ADEQ was scrapping its plans for a rooftop garden. Maintenance would have involved only some weeding and watering if there were a drought, he said.
"But typically after it's established, it's not a big deal," Robertson said. "So [the ADEQ] may have thought they didn't have the maintenance staff to do it, but that was never discussed with us in terms of what maintenance needs would be required."
Robertson said he didn't know what the ADEQ could have saved if it had installed the green roof.
A rooftop garden lowers the temperature of the roof, resulting in the need for less air conditioning in the building, said Mark Boyer, interim department head at the Fay Jones School of Architecture at the University of Arkansas.
The rooftop garden also acts as insulation, keeping the building warmer in the winter, Boyer said.
A garden roof adds years to the life of the roof, he said.
In addition, on a flat roof, the water drips off and then flows into the sewer system. With a rooftop garden, however, the rainwater lingers longer and benefits the garden, said Larry Merritt, a spokesman for the Chicago Department of Environment, which has experience with such gardens. Robertson said green roofs had the potential to capture and hold up to an inch of rainwater.
Boyer said he had been trying to collect donations to build display rooftop gardens. Then property owners "can understand what it is that we're talking about" and add them to their own buildings, Boyer said.
Robertson said one of the misconceptions was that rooftop gardens cost too much. But, he said, energy savings offset those upfront costs over the life of the roof.
"I think the perception of the expense is holding it back," he said.
Robertson also said another obstacle to the adoption of rooftop gardens is that property owners typically want to keep leaks and moisture off their roofs.
"The perception is that we're going to end up with roof problems with leaks and mold and everything else," he said. "And that's just not the case."
Related: Garden Roofs Blossom in Chicago