The idea of making gardens on rooftops of high-rise buildings, which was first floated in Iran in 2010, is now becoming rather a common practice in the polluted capital city.
Experts hope that the vogue of green rooftops, a luxurious option promoted by real estate agents particularly in the upscale districts in northern Tehran, will contribute to improving the stifling air quality, the Persian Daily 'Haft-e Sobh' reported.
Each one square meter of green space helps remove 500 grams of particulate matter per year. Trees are able to produce oxygen in their surrounding area but only as high as their growth. So, it would be a breath of fresh air if plants grew higher than buildings and what better place than rooftops.
To address the harmful effects of air pollution, making green roofs has become mandatory in many developed countries since the past half a century. In Iran however, the builders' love for ever higher profit has so far prevented them from considering the policy as a serious measure.
In recent years, sky rise greenery has become a common practice as green building certification moves into mainstream consciousness in major cities across the world.
A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage and irrigation systems. Recent discoveries in the field of light compound materials have facilitated such designs of roof gardens.
Green Benefits
Green roofs serve several purposes. They effectively utilize the natural functions of plants to filter water and treat air in urban landscapes. Also, insulation material used in green roof structures can help reduce the overall interior energy consumption of a building. Vertical green spaces, just like urban ones, can lower air temperatures and mitigate the heat island effect (warm urban areas due to human activity) through the process of evaporation. They can create a habitat for wildlife as well; many countries have provided the opportunity to practice bee-keeping for honey production.
Absorbing rainwater and providing an aesthetically pleasing aerial landscape, are among other benefits of green roofs.
However, it is important that the municipal authorities keep watch on the development of such roofs in Tehran as professional engineering expertise is required to build the green gardens. Not all buildings are able to support the weight of a garden and non-professional constructions can cause serious problems.
Case Study
In a case study on the city of Tehran, Kaveh Samiei, a landscape architect and expert in designing ecological high-rise residential complexes, says in the past many old Iranian cities like Isfahan, Shiraz and Tehran were garden cities and "nature was inseparable from urban areas." With modernism and urban growth, modern homes and high rise habitats replaced gardens.
Samiei was formerly a faculty member (as well as department head) in school of architecture and urban planning at the University of Semnan, Iran, where he was teaching ecological architecture; fundamentals of ecology; contemporary styles of architecture; and Persian and Japanese gardening.
The study, published in biotope-city.net points out that the fast growing populations and changes in life style contributed to the destruction of garden cities. Only a few of these gardens exist now, mostly in Isfahan, Shiraz and north Tehran.
Tehran's ecological structure has experienced numerous destructions with more than 12 million inhabitants and unbridled construction activity. The development of parks and public green space has not been able to restore the city’s green ambiance fragmented as a result of disorganized and uncontrolled growth, thanks to the controversial management of the Tehran Municipality.
The earlier remnants of natural and manmade ecological patches (ancient gardens, modern parks, open spaces, hills, and boundary forests) are under constant pressure of destruction due to urban development and the scarcity of land in the increasingly heavily built-up metropolitan areas, the study said.
Long Way
As a registered architect in Iran, Samiei is also an expert in designing ecological high-rise residential complexes.
"We are at the beginning of a long way in Iran (in roof-top/vertical greenery). There are a few programs which are partially working and some architects and environmental designers are trying to develop and use green textures. However, we need the experiments and knowledge of pioneers, particularly from similar climates. Many years ago European and North American countries established associations, institutes and communities for educational and networking purposes while hand in hand influencing or assisting governments to implement incentive and strategic programs. We can see the results in successful cities like Toronto, Chicago, and Stuttgart."
Planning for green roofs and living walls as important components of green development in urban areas, as well as guiding policy, providing standards and supportive regulations with sufficient awareness can improve and develop vertical greenery in Tehran and other urban areas of Iran, but "we need to go towards a green infrastructure framework bolstered by the research and experiments of others," he says.
