The Green Roof
Many urban dwellers experience the monotonous gray color in their area...are you one of those living in a high rise building where you only see cemented spaces, gravels or tins on roofs in your surrounding?
Today, I am sharing a topic about green roofs popularly known as Eco Roofs in Europe. In Austria, the government subsidizes the building of such roofs per square meters. Surveys done by the city admins noted that more and more green roof owners are satisfied and are having lovely experiences with their roofs. They are costly to construct, but then.. when subsidized it pays to make the effort because there are so many benefits that can be derived from having one installed.
The complex we live in as shown in the following images has Eco-roofs that are planted with succulents. Solar Panel are also installed in here to collect energy from the sun rays and convert this to warm energy used for heating and cooling.
All new buildings in Austria are encouraged to construct Eco Roofs because of its proven benefits not only to the dwellers but to the environment as a whole. The construction of this kind of roof is composed of many layers of materials ....for me, its most important aspect is purifying the air and therefore the air we breath is cleaner since air pollution is reduced.
The picture below shows the layer composition of this construction as explained by a case study of the below authors Ahmet B. Besir and Erdem Cuce. Source
Green roofs are structurally engineered and generally comprise of six key components as illustrated in the figure bellow. These are:
The uppermost planted layer. Success of any green roof depends on how healthy the plants are. The growth substrate which is the growing media and directly influences the plant growth and performance of green roofs.
The filter layerr which prevents small media particles (i.e. soil fines, plant debris) from blocking the drainage layer below.
The drainage layer which provides an optimal balance between water and air in the system. It is a key component affecting the amount of storm water which will be retained on the roof at any given time. It aids in the removal of excess water from the substrate and also improves the thermal properties of the roof.
The protection layer or protection mat which is used to protect the waterproof membrane from damage following installation. Usually, the protection layer is installed directly on the waterproofing layer or at the top of the root barrier layer, providing further protection against root penetration and doubling as a separation sheet.
The root barrier which protects the integrity of the roof from roots of plants that could penetrate from green roof’s upper layers. It protects the structure from damage.
The waterproof layerand the insulation are, of course, vital parts of any roof. Besides that, there are some additional components depending on the climatic conditions like irrigation systems.
Source: Green roofs and facades: A comprehensive review by Ahmet B. Besir and Erdem Cuce
Positive Benifits of Green Roofs...
One of the most positive benefits of green roof is it acts as purifier of the air, it converts the CO2 into oxygen which makes the air clean, it also act as a buffer of the rainwater which is transmitted to the plants and therefore avoids less draining of it in the sewage system. Besides all these, the birds and the bees and other insects are coming in and make the roof as their habitat.
We can save energy in cooling the inside of the house during the hot months since the green roof reduces the temperatures of the roof and therefore can save energy costs. Not only green roofs offer economic value but also it improves the well being of a person. Realty agents noted that the green roofs offer additional increment in the value of the house.
The green roof system has long been established in the city of Vienna. And as the city is expanding, more and more urbanization in the outskirts of each districts are following the trend.
The city as such is very green since not only green roofs are encouraged but also the greening of the vertical walls called Living Walls are also becoming popular like the image below of the MA48, the Waste Management Building in Vienna.
We hope to see more of these roofs at this time of climate change.... other cities are following this trend particularly in the EU
All images were taken and owned by 
except Image Nr. 5 and Nr. 8 which were properly sourced.
Until next time, keep safe everyone!