According to researchers at the Polytechnic University of Madrid, green roofs are more than just eye candy—they can also reduce building temperature, serve as insulation, and reduce noise pollution.
The researchers looked at roofing systems consisting of a layer of plants on top of a substrate that allows water to drain, a porous concrete layer that allows water to rise from tanks, and a waterproofing sheet to stop leaks.
According to the study, green roofs increase insulation no matter how well insulated a structure is.
This is not the first study related to green roofs. A study published this summer by the University of Texas at Austin involved the examination of six different green roofs and their ability to cool interior areas and capture rainwater. The study, which was based on research conducted in 2006 and 2007, showed that green roofs can reduce air conditioning bills by 21 percent compared to black-top roofs.
Additionally, the researchers noted that green roofs' ability to cool interiors and capture rainwater is improved with the use of native plants.
For a great example of a green roof in action, check out the newly renovated California Academy of Sciences.