Scott Helmes with RSP Architects has been one of the main drivers of the new green roof project at City Hall. Helmes started working on the concept for the green roof in 2005. The 5,000-square-foot green roof located in the interior courtyard of the historic City Hall and Hennepin Courthouse building is designed to have a number of environmental benefits, including capturing stormwater runoff, mitigating the urban heat island effect and making the building more energy efficient, among other things. Helmes recently sat down with the Southwest Journal’s Sarah McKenzie to discuss the project. To listen to a short clip of the interview, click here.
SWJ: What makes this green roof project unique?
Scott Helmes: [There were] big challenges because it’s in a courtyard. Big challenges because it’s in a 110-year-old building, of which the center courtyard was chopped up. No one knew much about the building that was added to the courtyard. Originally, one of things that we’ve always said is that the courtyard was done on a sustainable principle. In 1900, it brought light and air to the workers. They filled it up and caused a lot of drainage issues … It was not very aesthetic. … There is always structural issues of putting green roofs on existing buildings. …
We had some technical challenges to overcome, so we investigated a number of different things. We looked at solar, we looked at green roofs, obviously. We looked at rainwater management. We looked at green walls.
The green roof is the centerpiece. Our original design had more than one green roof, and we can still add more green roofs to the courtyard.
SWJ: What are the biggest misconceptions about green roofs?
SH: The biggest issue with a green roof is cost. Sometimes people think the cost of the green roof is exorbitant, but if you look at the lifetime cost, it pays back. The other part people have a misconception about is that its value is limited only to the building. In actuality, a network of green roofs really benefits the environment as a whole. People think, ‘That’s just a green roof — so what?’ There are two concepts that have been important to this sustainable project. One of them is rainwater. The second one is the urban heat island. We know for a fact that Minneapolis is four degrees hotter on any given day than a surrounding suburb. We also know that if we covered a lot of downtown Minneapolis with green roofs, we’d lower that to three degrees. …
The other misconception is that they are maintenance free. That is not necessarily true. You have to be very careful with the plants that you have.
… Green roofs are centuries old. They aren’t really a new concept, but what is different is there are a lot of new technologies to make them more viable.
SWJ: What would you like the public to get out of this project?
SH: It’s an interesting concept for me because the building is a 110 years old. City Hall was constructed on an older concept of civic pride. We seem to have lost that. There’s a lot of pressure on City Hall not to spend money on things. … A green roof and sustainable principles are important. … Putting a green roof on a courtyard is going to do some things for the employees because it’s going to be aesthetic and it’s going to improve the environment. … It’s about dealing with that issue — what should your public buildings look like? Should they be dull and monotonous, or should they be exciting and vibrant buildings that reflect today? And I think if you can keep a City Hall contemporary, this is one way to do it. We have a responsibility as a public to use those principles where we can. I think there is some foresight there to do [the green roof project]. Whether it’s a green roof, solar panel, or a cistern, I think the philosophy and concept is really critical to City Hall. … I think it’s the responsibility of government to be environmentally responsible.