How Eco-Friendly Green Roofs Save Energy, Conserve Water and more; Clean Up Cities
If you were a bird flying over any major metropolitan city in the world, your eyes would be greeted with a vast expanse of black tar or asphalt that makes up the roofs of most urban buildings.
And you would feel warm. Very warm. That’s because of the “urban heat island effect” created by radiation of heat from dark roofs which barely soak up any of the rain water that falls on them.
Conventional roofing is destroying our cities and crippling our environment.
Enter the green roof. It has revolutionized roofing in the modern world, and brings several benefits to home owners, businesses and even entire cities. Green roofs protect and preserve the environment, conserve water, and even help save energy. They convert what used to be ‘wasted space’ and turns it into something useful.
The Growing Appeal of Green Roofs
Green rooftops have been popular across Europe. They are only now making themselves attractive to building owners across the United States, Africa and Asia. The recently constructed East African Coca Cola headquarters building in Nairobi, one of the most expensive buildings in Africa, boasts of an extensive green roof with a garden that doubles as a place for employees to relax and use for recreation.
Green roofs covered with vegetation can help cool down building interiors and save energy expenditure on air-conditioning. Plants and even small trees can be grown on the roof, which helps restore city environments that have been devastated through the construction of high rise apartments and buildings. These plants compensate for lost vegetation during construction, and also absorb the carbon dioxide emissions responsible for a greenhouse effect of global warming.
Green Roofing Adds Without Subtracting
The nice thing about green roofs is that they restore the balance of greenery in the city without adversely impacting urban infrastructure.
Not only are green roofs prettier, they are longer lasting than regular roofs and insulate buildings against heat loss or gain. Where water typically bounces off asphalt roofs and streams down conventional roofing, it is partly absorbed by a green roof which thereby reduces the need for expensive drainage systems.
Installing a green roof does take some special preparation including the laying of multiple layers to protect buildings with a waterproof membrane. If desired, water treatment plants can also be installed on roofs, with water from showers, sinks and baths being purified and recycled, saving on water related expenses by upto a third. And green roofs absorb 95% of rain water, helping irrigation and lowering storm water runoff. The lush greenery even attracts birds and small animals which make up a part of the thriving rooftop habitat.
The Cost of Green Roofs
Green roofs can be expensive, with typical costs running from $10 to $20 per square foot. But by no stretch can green roofing be considered an ‘expense’ because the very installation of such a roof will immediately enhance the value of a building by nearly 25%.
Layers of plants on a green roof protect the underlying membrane against damage by nature, enhancing their durability and extending the longevity of a green roof. These benefits have led to a resurgence of interest in green roofing across the United States, with growth rates of 28.5% in 2010 being reported.
Germany is the world leader in green roof technology, and Europe as a whole has reported 15% growth per year in green roofing solutions. And this is only set to keep growing steadily as discerning home owners evince keen interest in embracing green and environment friendly practices.
Governmental support has also helped in popularizing green roofs. After Chicago’s City Hall got a green roof, the Mayor pushed for green rooftop systems, encouraging adoption through a series of incentives and grants. This, coupled with the inevitable drop in prices as the industry grows, will ensure that more eco-minded home owners and commercial building owners will move towards green roofing.
About the author:
Bertram Wentzler blogs about green roofing.