Green Roof Systems

Are you one of those people who are blessed with a green thumb? Well, conventional gardens are passé these days! How about utilizing your talents to planting on your roof? Yes indeed, a trend that was begun in Germany is catching on in the US, which seeks to alleviate ecological problems like greenhouse warming in urban areas and storm water runoff. Yes, a green roof system does that and more!

What is a Green Roof System?

A green roof, also referred to sometimes as an ecoroof, as is quite evident from its name, means growing plants on the roofs of buildings. In other words, it is about replacing conventional roofing material with a living system of vegetation, compost and soil, which is lightweight. It is not just about the aesthetical value it provides, which it does, but is about creating a green layer on top of the building you live in, which makes the environment you live in better. Besides the environmental benefits that occur locally, according to studies it has been found that green roofs lower the costs of maintaining roofs as well as the use of energy due to providing insulation to buildings which protect them from extreme temperatures.

This is not a new technology. After several decades of putting it into practice, the Germans, who often find themselves cramped for space, have perfected this idea into a fine art. According to estimations, it is thought that about 10 percent of German houses have green roofs. In fact, about 350 million square feet of green roofs have been installed in Germany from 1989 to 1999, and this trend is continuing to grow.

What are the Uses and Advantages of Green Roof Systems?

In the areas that have a combination of storm water and sewer systems, when there are heavy storms, it results in overloading the wastewater system, causing it to flood. This, in turn, results in raw sewage being dumped into the local watercourses. It has been found that green roofs slow down the rate of storm water runoff and also reduce the total amount of runoff from the roof. Green roofs, in fact, have the ability of retaining as much as 75 percent of rainwater, which they then release back gradually into the atmosphere through transpiration and condensation, while they keep back the pollutants in the soil.

Another use of green roof systems is dealing with the heat island effect in urban areas. Conventional buildings absorb the radiation form the sun, re-emitting it has heat, which makes urban areas about 4 degrees C, or 7 degrees F, hotter than the areas surrounding them. However, the temperatures on green roofs on hot days are 14 to 44 degrees C, or 25 to 80 degrees F, cooler compared to conventional roofs in the vicinity.

Green roofs also improve the insulation of roofs where they are installed. According to studies conducted by environmentalists, it has been found that installing green roofs results in reducing summer cooling requirements by 26 percent and also reduces the winter heat losses by 26 percent. Moreover, installing a green roof also helps in lengthening the lifespan of a roof by two to three times.

And lastly, green roofs help in providing a habitat for animals, insects and plants, which usually have no space in urban areas. It has been found that green roofs, even up as high as 20 stories, attract butterflies, bees, birds, and other insects. Green roofs can also act as sanctuaries for migratory birds, songbirds and so on, which increasingly have to contend with shortages of their natural habitat.