Green roof or living roof refers to such building roofs which are completely or partially covered with greenery. Where the Go Green approach is getting more popularity in the world latest equipments have been invented to overcome the increasing pollution issue on our planet, green roofing will not only look an attractive view for many of the viewers but also it will clean our atmosphere from carbon gases. Such buildings can be named as truly dedicated green environment caring, while these plants or greenery is planted over the waterproofing membrane of the building. Green roofing has also additional layers on buildings such as irrigation systems, drainage and root barrier. The green here is not referring to green color of the building, but green environmentalism adopted buildings.
Although some people in debates may also refer the container roofs where plants have been maintained on spots are named as green roofs, but they are not true green roofs. But rooftop ponds which are used to treat grey water are basic form of the green roofs. Green roofing basically serves the purpose to clean the environment with more greenish look beside us. It is not only the greenery covered lands and big forests which can minimize he carbon dioxide, but in urban areas where not even enough space to build the parks, such green roofing system will be the right eco-friendly solution.
- Green roofing serves many purposes for a building, just like;
- To mitigate the heat island effects
- Providing the insulation
- Lower down the temperature of urban areas
- Creating habitat for wildlife, and
- Absorbing rainwater
There are two basic types of green roofs;
- Extensive roofs,
- Intensive roofs
Intensive roots are thicker and support the thicker plants which need more maintenance and support. In extensive roofing, the roofs are covered with light layers of vegetation. They are light weight than intensive roofs and cannot support the heavy plants to support them. The green roofing term is also used for such buildings which are using some form of green technology or contributing to eco-friendly products building. Some buildings which are using solar thermal panels and collectors of solar energy as well as photovoltaic panels are also included in green roofing terminology.
Environmental benefits of Green Roofing
There are tremendous benefits of green roofing due to several positive effects of plants and vegetation on our environment. Green roofs contribute positively in our environment to;
- Reduction of heating by adding thermal resistance mass and value. According to a research study done by Brad Brass from University of Toronto, it was found that green roofs have reduced the energy consumption and heat loss during the winter peaks.
- Reduction of cooling loads on buildings up to 90 percent, when green roofs have been designed accordingly to act as passive solar of heat reservoir and terrarium. Due to green roofing, the average temperature of urban areas during hot summer seasons will highly be decreased.
- Natural habitat creation.
- Help reducing the storm water and run it off.
- Many diseases in human beings are due to increasing rate of carbon dioxide and other hazardous gases. Green roofing filters the carbon dioxide and other pollutants and contributing to lower down the disease rate, e.g. asthma.
- Green roofing filters the heavy metals and pollutants out of rain water.
- Soil used for vegetation and greenery will be used to blow lower frequencies and insulate the building, whereas plants will block the high frequencies.
- It will contribute to more LEED points on the building, if green roofing has been applied correctly.
- In urban areas where space for agriculture is much less, this will help to create more space for agriculture
- In green roofing system, water is taken by plants to store in substrate and then returned in to the atmosphere and evaporates.
- Green roofing not only stores the water and cleans the atmosphere but also it will moderate the water temperature. In this way, green roofs help as natural filters for the water which will otherwise run off.
Financial benefits of green roofing
- The local and federal tax incentives
- Tax reduction for storm water
- It increased the real estate value
- Dramatically increasing the life span of the roofs
There are several studies carried out about green roofing and its benefits in Germany since from 1970. Green roof is a key component of autonomous buildings. In Germany, Berlin is considered one of the largest centers where continuous researches about green roofing are being made and in last ten years, thousand of researches have been made there. There are nearly about ten green roofing researches centers which are currently working in United States. These green roofing centers are expanding their activities in forty countries in Asia, Europe and North America. According to recent researches done in Greater Manchester area about green roofing, it was found that green roofing has helped to lower down the temperature in cities. If green roofing is perfectly adopted in heavily populated cities, the positive results will bring the atmosphere to as green as it was in between 1961 to 1970 in United States.
Green roofing will make a biggest difference where buildings are high and more populated with high evaporation fraction is low. A major difference due to green roofing was found in most of the town centers. Latest technology based green roofs which are prepared of a system of manufactured layers will support the roofs growing for medium size vegetation. Green roofing is not something a new concept, in Northern Scandinavia the green roofs have been from many of centuries. The modern trend of green roofing was however started after 1960s environmental control efforts in Germany.
Today, more than 10 percent of roofs in Germany have become greenish with these eco-friendly techniques and same results have been found in United States where huge population increase created the bigger pollution issue. In European countries, there are also many active associations which are performing their role best to promote green roofing.