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City's living roof gets revamped for low maintenence (6 Photos)

The original green roof was installed a decade ago

While a green roof was part of the construction of Guelph’s City Hall a decade ago, the current version is one that was installed a couple of years ago.

“We took the old soil off and the vegetation and we inspected the roof underneath just to make sure it was in good condition and we put new stuff on top,” said Jean Starchuk, the city’s project manager for facilities renewal, facilities management, infrastructure, development and enterprise services. She’s been with the city for three years, overseeing renovation and construction at city facilities.

The original green roof was installed in 2009.

“It was part of the new construction,” Starchuk said. “When it was newly being constructed, there definitely were goals when it came to sustainability.”

Some of those goals included absorbing stormwater, increasing the building’s energy efficiency and giving plants and pollinating insects a place to live.

Two years ago the original soil and plants were removed and replaced.

“My role was to kind of remove the soil and the vegetation that was up there and put new stuff that was low maintenance,” Starchuk said.

While that conjures up images of workers hauling wheelbarrows full of soil through City Hall’s lobby and up and down the elevators, that just wasn’t the case.

“They hung like a tube on the side of the building and got rid of the soil that way versus bringing it through and then actually shot new soil up from the outside.”

That was accomplished during a few months in the fall of 2017.

“When we redid the roof, my goal was to put soil up there that would be very weed resistant and something in plants that wouldn’t need irrigation and would kind of do well with very little maintenance,” Starchuk said. “There was a whole list of plants put together by a consultant that we chose to work with.”

In all, a total of 6,410 plants of varying sizes were put on the roof.

“There are a bunch of sedums and then some more flowery type species,” Starchuk said.

The flowery types include three varieties of allium (a taller plant with a ball-type flower), Coreopsis lanceolata (a smaller plant that has yellow daisy-like flowers), phlox, Hylotelephium and Penstemon hirsutus that has a bell-type flower.

When considering which plants to install on roofs, there are several factors that needed to be taken into consideration. The plants have to withstand hot summers and cold winters and could also be subjected to long stretches with little rainfall.

“So far so good,” Starchuk said. “It’s been pretty low maintenance and that was what we were mainly looking for.”

While the citizens of Guelph can’t get out on the roof itself, they can take a look at it if they so desire.

“They could come and see it,” Starchuk said. “They could come to the fourth floor and have a lookout.”

Many windows on the upper floors of City Hall do look out onto the green roof, making anyone working out there feel as if they’re in a fishbowl.

The soil around 10 centimetres in depth was put on the living roof, which measures about 5,800 square feet when it was redone in 2017.

Last year a bee condo was installed on the roof with the goal of attracting the loner bees, the ones who basically keep to themselves and aren’t members of a hive. The small wooden structure is designed to give the bees a place to rest and possibly hibernate.

“We have the bee condo up there now. It’s a work in progress I would say,” Starchuk said. “The bees that are up there, and I’m no expert, are kind of the more solitary creatures that come and go so you’re not going to see the kind of activity you’d see around a beehive.”

The current edition of the green roof is basically the final version.

“As we monitor how things grow, we might add more plants in that are bee-friendly,” Starchuk said. “That’s what it’s going to look like, but the plants would get bigger over time.”

The green roof at City Hall is certainly not the only one in town as there are several including ones on Skyline and University of Guelph buildings and Delta Guelph Hotel. Starchuk would certainly recommend others to follow a trend that has been growing in recent years.

“I think it’s much more exciting than your standard roof that’s not too attractive to look at.”

The living roofs also offer another benefit that isn’t thought of often.

“It’s actually protecting the roof underneath so you actually get a longer lifespan because it is protected underneath,” Starchuk said. “It’s all protected underneath. You do have to make sure the water drains properly so it’s not just sitting there on the roof.”

While Starchuk doesn’t get on the roof often, she does enjoy any time she can spend there.

“I actually find it to be a very peaceful environment, but people can stare at you when you’re on it. I think it’s a nice spot. It’s a nice piece of city hall.”