Roof sprouts green future for UNL

Photo

Dave Schmidt pulls out one of the unusually long plants from the green roof at the Whittier Building.

Story and photos by Sara Nelson, NewsNetNebraska

Despite some unexpected bumps in the road, landscape architects consider the Whittier Building’s green roof – a first for the University of Nebraska-Lincoln – a success so far.

“It’s really, in this instance, just about learning how to care for [a green roof],” said Emily Casper, a UNL Landscape Services architect. “It’s just about getting experience.”

The department is monitoring the success of UNL’s first green roof, installed in mid-June at the Whittier Building, to determine its practicality for future projects.

Although the environmental benefits of green roofs are clear, the time investment for maintenance and care of the plants was an unknown until the university tested the technology first-hand.

“Monitoring everything has gone well,” said Kirby Baird, City Campus landscape manager. “Except for a couple times when it was really hot – we didn’t have to water.”

Baird said because of unusually high rainfall this year, he anticipates the roof will require more frequent watering in years to come. Between watering, weeding and clipping, the maintenance of the plants averaged around two hours of work a month.

Drought-tolerant sedum plants require little care.

If the plants needed excessive maintenance it would mean hiring an extra employee to care for the roof – a cost Landscape Services does not want. So far, the extra care the Whittier Building’s green roof needed was because of its unusual location.

The green roof at the Whittier Building is not entirely conventional. The roof sits in a courtyard, atop a utility tunnel, three stories from the top of the building.

Dale Schmidt, Landscape Services area supervisor, said sunlight and rain reached plants unevenly because of the roof’s location. These unusual conditions made the plants grow unevenly and some plants grew unexpectedly long.

Landscape Services officials worry that the unusually long plants will mat down during snowfall this winter and could kill plants.

Because of these concerns, Schmidt spent an hour hand-clipping the plants that were too long. He predicted this would not be a problem on an exposed green roof where the elements hit the plants more evenly.

Winter’s impact is still an unknown. “I think it will be interesting to see the different levels of snow because it’s inside a courtyard and it’s three stories down, it will be something to watch,” Casper said.

Baird also has concerns about the green roof’s first Nebraska winter. He said his concern is how the plants will handle the first frost. He’s worries some plants will die even though they are somewhat insulated in the courtyard.

“The important thing to remember is that this is learning experience for everybody – for facilities, for the university as a whole,” Casper said. “We’re just trying to get our feet wet and learn.”

But now that the department has some experience with a green roof , it can more confidently suggest them for future projects.

“In my opinion, they would be something we would push as a department. I think especially as we get more experience with it,” Casper said, “That also means we need to evaluate how we take care of it – that’s why we are watching it to see how much time it really takes.”

In the past, green roofs were planned for other buildings but were trimmed with budget cuts, Casper said.

The cost varies greatly depending on the type of green roof installed and it is hard to pinpoint how much they are going to cost, Casper said.

“There’s plenty of opportunities for green roofs in new construction projects,” said Ted Weidner, assistant vice chancellor of facilities, management and planning, “I’m a little concerned about the renovation projects where the building might not be built the right way. There’s a lot of costs associated with taking some corrective actions.”

There are no immediate plans for another green roof at UNL. Landscape officials hope after a year of monitoring they will be able to push harder to get more green roofs on campus.

The benefits of the green roof technology range from energy conservation, noise reduction to fire prevention. Watch this video describing the advantages of green roofs.

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