Everything that was old is new again. As we continue to look for the latest, cutting-edge green technology, it’s not surprising to learn that some of the best new ideas are decades, if not several millennia, old. Growing plants on the roof is one of the current up-and-coming technologies in the U.S. with its roots (get it?) based in ancient history.
A green roof system can be an addition to a building’s existing roof or designed into a new home. Basically, it’s a multi-layered system that begins with the structural roof support, with a vapor barrier and thermal insulation on top. From there, a support panel is installed, followed by a waterproof/root repellent layer. A drainage layer comes next, followed by a filter membrane, and then finally the growing medium and vegetation. (That’d be the peas and carrots, or for some, the weed bed.)
Although the technology has improved significantly with the advent of modern man-made materials, the Hanging Gardens of Babylon were actually green roof systems! Not only did they provide King Nebuchadnezzar II’s wife Amyitis a feel of her home country, but also offered insulation benefits as well. That combined with good solar thermal design gave the lovely couple a very comfortable home!
With today’s green roof technology, there are even more benefits to be had, including:
- Heating and cooling energy savings
- Increased lifespan of roof membrane
- Green roofs are excellent sound insulators
- Reduced size of HVAC equipment
- Reduced amount of standard insulation needed
- Reduction or elimination of roof drains
- Increased aesthetic value
- Possible food production
Green roofs are popular in many European countries, thanks to government support. In America, the idea is slowly catching on, especially as we begin to realize not only the cost benefits, but the social and environmental benefits of green roof systems as well!
Posted on September 28, 2009