Have you ever worked outside in your flowerbed on a day when the sun never seems to disappear into the clouds? As you dig up old plants and replace the empty spots in the soil with fresh flowers you think to yourself, “If this shade tree wasn’t here, I might just pass out from exhaustion!” Well now imagine carrying out that same sweat-wrenching chore on a rooftop. With new research from the Polytechnic University of Madrid (UPM), gardening may literally move to the next level as new sustainable garden roofs are developed.

Researchers from UPM built a roof covered in plants, along with a watering system, in hopes of improving a building’s heating and cooling system. The study tested multiple roof supports and plants to determine which plants work well together to reduce energy consumption inside of buildings. This new roof is described as a “’rurban’, sustainable architectural solution” that will help in reducing environmental and acoustic contamination levels in urban areas.

Scientists discovered that native plants performed best on a roof with an irrigation system and an 8 cm tank that allows rainwater to collect. The roof is divided into layers, the first layer being a light substrate, such as crushed pine bark, that will ensure that the plants do not drown. As the substrate rests on porous concrete surface, excess water is drained into a tank and water will later rise up to the roof through capillary action, enabling uniform irrigation.

These “rurban” style roofs will ultimately aid in reducing the temperature of cities, as well as reducing acoustic contamination because of plant absorption. Though the roofs will benefit the environment, development of the new building material is slow because of high prices.

Link to News Article: http://www.sciencedaily.com/releases/2008/11/081121151914.htm

Link to News Release: http://www.alphagalileo.org/index.cfm?fuseaction=readrelease&releaseid=534128 (Original article in Spanish: Francisco Javier Neila González, César Bedoya Frutos, Consuelo Acha Román. “Las cubiertas ecológicas de tercera generación: un nuevo material constructivo”. Informes de la Construcción 60 (511)15-24, 2008)

Discussion Question: What other materials could be used in building construction to reduce pollution?