Green Building Features

Navigation Map Click on the images above to learn about the features of the building.

 

 

 

Chicago City Hall's Green Roof. Photograph Courtesy City of Chicago.Green Roof

What is a green roof?
An alternative to traditional roofing materials is a “green” or “vegetative” roof.  A green roof system  is covered with vegetation and includes a special soil medium,  waterproofing membrane and  drainage systems (more complex systems can include  irrigations systems and other features). The green roof system is used extensively in Europe, and is gaining favor in the US based on its ability to mitigate storm water run-off and extend roof life by 20 years or more over traditional tar-based materials used primarily on flat or low-sloped roofs.

What is not a green roof?
A true green roof is not the plants in containers that you maintain in your rooftop garden, lovely as your container garden may be. It is a complete roof structure that has been analyzed for load-bearing capacity and wind shear, and is planted with vegetation that can withstand harsh temperature and other weather conditions. 

What are the benefits of a green roof?
When you think of all of the hard surfaces in a town or city like roads, pavements, parking lots and roofs, it is no wonder that rain events lead to stormwater management challenges.  A major benefit to green roofs is that they hold and slowly release water, which means storm water can be handled by existing pipes and related infrastructure – this helps with water quality and erosion.  Green roofs also help reduce air pollution, conserve energy, absorb and reflect ultraviolet radiation from the sun (which contributes to roof degradation), and protect against extreme temperature fluctuations that cause roofs to expand and contract, and eventually fail (the last two benefits lead to the doubling and sometime tripling of roof life).  Last, but certainly not least are the aesthetic and wildlife habitat benefits of green roofs – can you imagine the transformation of towns and cities if most buildings had green roofs? 

 

For next feature... Photovoltaic

 

 

Large Image: Chicago City Hall's Green Roof. Photograph Courtesy City of Chicago.