September 09, 2019

Why the green roof needs its moment

Green Infrastructure

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When we think about green space, we often think about parks or large swathes of grass where people can play or relax. We often forget about rooftops—a highly underutilized space that frankly should be overutilized given how many private and residential buildings make up a significant amount of land area in our cities.

If you’re unfamiliar with the concept of green roofs, or what exactly a green roof is, it’s “a rooftop that is partially or completely covered with a growing medium and vegetation planted over a waterproofing membrane.” Moreover, one of the rooftops biggest strengths is its ability to offer a more beautiful view of our cities’ infrastructure.

A green roof’s impact extends far beyond aesthetics, however, touching on our mental, physical, emotional well-being, while also addressing environmental issues, such as air quality, stormwater runoff and energy use, and food sustainability.

So, let’s dig deeper into the benefits of a green roof, and why we should look for opportunities to incorporate this piece of green infrastructure into our cities and town.

Health and Wellbeing

At Nadi, we understand the relationship between humans and nature as positive and beneficial to our emotional, mental and physical health. It’s why we advocate for green space—especially in urban areas and cities.

Amy Chomowicz, a Program Manager at the City of Portland and the Secretary at the Green Roof Info Think-tank, explains: “Humans have an innate connection with the natural world – the concept of biophilia. Decades of research, data, and analysis have demonstrated that our physical and mental health and well-being is improved when we strengthen and reinforce that connection.”

A great example of this connection resides in St. Louis, MO. The Olson Family Gardens at the Saint Louis Children’s Hospital is located on the eighth floor of the hospital, “containing over 7000 varieties of plants ranging from sedums to large flowering trees.”

 

Olson Family green roofIncorporating a green roof or Healing Garden feels poignant and necessary in this type of setting. It reinforces the connection that Amy Chomowicz highlighted, illuminating the real and tangible benefits that not only affect patients but hospital staff as well.

“Facilities that incorporate accessible green and open spaces within the campus aid in the recovery of the patients as well as improving the working environment for the healthcare providers and visitors,” writes John Robinson for Living Architecture Monitor.

The Olson Family Gardens offer a reprieve for family members, patients and staff from the controlled chaos of a hospital. As the hospital’s chaplain Rev. Connie Madden describes it: “a sanctuary [where] people go to feel safe and less harried.”

Olson Family green roof
With winding walking trails, places to sit and water features, such as waterfalls, fountains and goldfish pond, it’s easy to see why patients and staff at Saint Louis Children’s Hospital view the Healing Garden as healing and comforting. We’re happier when we are in nature.

Food Security and Sustainability

According to the 1996 World Food Summit, “Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life.”

Food deserts are a real issue in many urban environments—even in developed countries like Canada. In fact, a University of Winnipeg study revealed more than 120,000 residents live without proper access to food in our city. So, what can we do to prioritize food security and healthy eating in the planning of our cities?

Giving people the ability and autonomy to grow their own food can alleviate these issues. Canadian universities such as Concordia, Ryerson and the University of Saskatchewan have reaped the “benefits of growing fresh food for consumption right on campus.”

Ryerson-University-Mind-Action-rooftop-garden

As Leanne Delap writes for Maclean’s describes the impact of Ryerson’s the 10,000-sq.-foot Ryerson Urban Farm atop the George Vari Engineering and Computing Centre. She writes, “The Urban Farm now operates on a five-year crop rotation; there are 30 different crops and hundreds of cultivars. Members from the student body, staff and surrounding community all tend to the space and take home a basket of food a week as return on investment… The yield is some 8,000 lb. a year.”

That is an astounding amount of food, not to mention a vital opportunity for community building on top of providing healthy food for residents.

Global warming and the environment

There are many benefits for people when we re-approach how we design rooftops. However, utilizing a building’s roof can be just as beneficial to the environment as it is to our health and well-being.

However, what I haven’t mentioned yet, is that not all green roofs need to be for public use. Its sole purpose can be to address global warming issues like the urban island effect that contribute to climate change. Moreover, a green roof can reduce stormwater runoff, energy use and carbon, while improving air quality, biodiversity and natural habitats. chichall1

Chicago addressed their own urban heat island effect and air quality control with the construction of a 38,800 square foot (total roof area) semi-extensive green roof at City Hall in 2000. At this time, it was a unique and unheard-of solution to mitigate urban heat island effects.

chichall9The rooftop garden boasts “over 20,000 herbaceous plants installed as plugs of more than 150 varieties including 100 woody shrubs, 40 vines and 2 trees – a Cockspur Hawthorn and Prairie Crabapple.” Moreover, rainwater is collected and saved for a supplemental irrigation system for establishing plants and additional water for extreme periods of drought.

While the public cannot access this space, it does benefit from it as it provides a cleaner and healthier world to live in.

Conclusion

The benefits are not only studied but realized in the real world. Not only do green roofs improve our health and well-being, food security and environmental protection, but they improve the local aesthetics of our communities, increase recreational opportunities and build social capital.

I’d like to see cities and developers consider green roofs, not only for new buildings but older ones as well. I look at buildings in Winnipeg, and wonder what City Hall would look like with shrubs, vines and trees coming from the roof?

While I know, we can't transform every roof into a green roof (not every roof is functional for green infrastructure), but there is a need to examine our current infrastructure and find opportunities to implement elements of a green roof when possible.