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Practicing Green Roofing

Green Roof policies can play a very important role for sustainable urban planning and climate change adaptation.Wolfgang Ansel, Director, IGRA explains the Green Roof policies that can help to implement the environmental technology and the successful development of a Green Roof market.

If you compare Green Roof Policies in the US and Europe,what is the biggest difference?

There is a strong focus on Green Roof regulations in Europe. But the cities are also using financial or non-financial incentives and public relation activities to accompany this process. Very often we can find akind of “carrot and stick” approach.Dr. Heleen Mees from the University of Utrecht has investigated the governance arrangements for the support of Green Roofs in different European and North American cities. Her thesis “Responsible Climate Change Adaptation– Exploring, analyzing and evaluating public and private responsibilities forur ban adaptation to climate change” shines a light on the differences.

Do you have the feeling that the municipal Green Roof initiatives have increased in the last years?

We see this trend at the international level. Urban heat island effect, flooding,poor air quality or the loss of biodiversity – the increasing urbanization leads to similar environmental problems all around the world. Green Roofs are an effective and cost-efficient technology to improve the green urban infrastructure. Many cities have recognized that in the mean time.

Which city has the oldest Green Roof policy?

I can’t vouch for it, butI think Stuttgart in German yis the municipal Green Roof pioneer at the international level. The first Green Roof regulations in Stuttgart came into force in the 1980’s. This policy was supported by a financial incentive programme for voluntary constructed Green Roofs. In order to make Green Roofs happen, delegates of the municipal departments,stakeholders of the developing Green Roof industry and Green Roof lobby groups worked hand in hand. The main ecological driver for the policy was the location of Stuttgartina basin with poor air ventilation and on the other hand the fast economic development of the industrial hub in south-west Germany, which resulted in high levels of soil sealing.

Is there a recipe for the success of a Green Roof policy?

I would like to make an important point at the institutional level. The educational work has to address the municipal administration and the political decision makers.This is important because the city should develop a guiding inter departmental principle for the promotion of Green Roofs. This might be a complex and lengthy process.But once Green Roofs are firmly anchored in the municipal guidelines, the topic will take on a new dimension.Munich and Stuttgart in Germany are very good examples for this process. In both cities it is a well-accepted standard that all new flat roof buildings should have a Green Roof. And both cities have more than one million square meters of Green Roofs. I would also recommend introducing the position of a Green Roof manager at the administrative sector. A person, who pulls all the strings and coordinates the Green Roof strategy. Other wise there is a risk that the Green Roof initiative fails to be effective.

How important is the information exchange in the field of municipal Green Roof strategies?

To support the information exchange on an international level is the basic motivation of our International Green Roof City Network. We are now able to launch the online platform of the network. Cities, which begin to explore the Green Roof topic can find a lot of valuable information about Green Roof policy instruments and the development of a Green Roof strategy. The practical case studies can also help advanced Green Roof cities to review their policies. Currently, 23 municipalities from 14 countries are participating in the network and this number continues to grow.

What is your favorite Green Roof benefit?

It is really hard to say what my favourite Green Roof benefits. There are so many ecological and economic advantages. And every client can have a different focus. We need to take this into consideration when we promote and design Green Roofs. But let me look at Green Roofs in a broader way. From my point of view one of the most important things is to show that the roof isa valuable open space. Imagine new building with a room that is locked up and can’t be used by anyone. Of course the investor would agree that this is a waste.But if we look at aerial pictures of cities we can see a lot of unused open space on top of flat roofs.

People seem to accept this waste of space as normal.If we can make them see the development potential, we achieve a great deal. I remember statement of the mayor of Hamburg at our 3rd International Green Roof Congress in 2013.He presented his vision for-Hamburg’s roofs cape in the future. Flying over Hamburg in 2030 he wants to see a green colored pattern of roofs for environmental protection or with leisure areas for the citizens of Hamburg. This year Hamburg has put a comprehensive Green Roof strategy into force to make that vision come true.

Excerpts from the Interview
International Green Roof Association
(IGRA) Newsletter

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