green roofCities across the globe are continuing to find smart and sustainable, environmentally-friendly and cost-friendly ways of incorporating climate neutrality into their designs. One hobbit-esque idea places gardens on the roofs of buildings, which has been met with great success in projects across the United States, and the world.

Macalester Green Roof Project History

Macalester currently has two green roofs – one above the fishbowl connecting the Turck and Doty residential halls, and one on the Kagin rooftop. The two Macalester Green Roofs began as student projects organized by MacCARES (Macalester Conservation and Renewable Energy Society).

The green roof on the fishbowl was completed on April 14, 2006. It was led by the MacCARES green roof task force made up of Alese Colehour ’09 and Ellie Rogers ’09 in association with Green Roof Blocks, Aloha Landscaping, Rosenquist Construction, and Facilities Management.  The green roof on Kagin was completed in 2007 by students Alese Colehour, Timothy Den Herder-Thomas, Angelina Lopez, and Ellen Rogers with faculty advisement from Dr. Jerald Dosch and Dr. Dan Hornbach. Both projects were completed nearly entirely from outside funding, and the green roof on top of Kagin has been used as a learning tool to measure runoff rates, rain levels, pH, nitrogen, insulation, and infrared scanning.

These projects are a part of MacCARES' greater goal to reduce carbon emissions, in line with Macalester’s carbon-neutrality goal. The self-sustaining green roof, also known as a living roof, is a cutting edge solution to reduce emissions and the negative impact of climate change, while acting as a long-term solution to saving money for our campus.

Benefits of Green Roofs

Ecological Benefits

  • Mitigates urban heat island effect:  Green roofs cool and humidify the surrounding air creating a microclimate which has beneficial effects within the immediate area. Instead of using concrete, which absorbs and retains heat, green roofs channel light and heat into a resource, leading to an overall cooling effect.
  • Natural habitat for animals and plants:  Green roofs create biodiversity and encourage wildlife, such as birds, butterflies and insects, to remain within urban areas.
  • Reduction of dust and smog levels:  Green roof vegetation helps to filter out dust and smog particles. Nitrates and other aerosol contaminants are absorbed out of the air and rainfall and bound within the soil.
  • Reduction of runoff:  Green roofs retain stormwater, alleviating stormwater infrastructure systems that would otherwise run into the Mississippi from campus, and use it as a resource instead.

Economic Benefits

  • Vegetative surface reduces heating and cooling consumption – if all of Chicago’s building’s roofs were greened, peak energy demand would be cut by one small nuclear power plant!
  • Reduction in consumption means reduced energy costs.
  • Protection of the roofs structural elements from wind, rain, sun and temperature fluctuations.
  • Extend the lifetime of roofs by 30 years by enhancing the roof membrane durability.
  • Increased property value through enhanced visual appeal.
  • Lower stormwater and utility fees, tax credits and grant subsidy programs.

Aesthetic and Psychological Benefits

  • Simple enjoyment of nature and the outdoors, a welcome respite from living in a concrete jungle.
  • Fosters a sense of community by engaging in this project together.
  • Blends buildings into a more natural environment, which promotes biological diversity.
  • Promotes an understanding that buildings and suburban areas don’t have to be eyesores, and that building sustainable futures is becoming part of the very fabric we live in.

How to get involved

If you want to get involved with more sustainability events on campus, including the green roof, please contact the Sustainability Office in Kagin, or email them at .

Add your project to the list

MacCARES (Macalester Conservation and Renewable Energy Society) is heavily involved with on-campus student sustainability projects. If you are interested in joining them, or contributing ideas, please email them at .