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Reporting on the 2nd International Green Roof Congress 2009
Bringing Nature Back to Town

By Christine Thüring
June 20, 2009

All Photos Courtesy Christine Thüring unless otherwise noted.

Flying over the new part of town on the Zeppelin NT - greenroofs galore!

From May 25 – 28th 2009, representatives from five continents came together to celebrate and discuss green roof technology in the municipality of Nürtingen (~30 km south of Stuttgart).  The 2nd International Green Roof Congress 2009 was jointly hosted by the International Green Roof Association (IGRA) and the German Roof Gardener Association (DDV), with patronage from the Federal Ministry of Transport, Building and Urban Affairs.

Delegates attended the 2nd International Green Roof Congress from 40 countries!  Map Courtesy IGRA.

Compared to the first event in 2004, this second congress featured speakers from 10 countries and drew 270 delegates from 40 countries.  Simply walking the exhibition or meandering through a coffee break was akin to moving through an international airport.  While English was the primary language, countless accents were undeniably present and many original languages rang out in communicative chorus.  When recalling the diversity of professions in attendance (architects, roofers, botanists, developers, academics, planners, etc.), and combining this with the internationality of the assembly, one gains a sense of how exciting and significant green roof technology has become, if only in cross-linking boundaries and cultures and overlapping disciplines.

The Municipality of Stuttgart; Photo:

European and Eurasian presence extended across the full geographic range, from Ireland and Spain, through Israel, Macedonia and Serbia, and everything in between.  Asia/ Oceania sent representatives from China, Thailand, Singapore, India and Australia, while the Americas sent professionals from Chile through Brazil, up through Montserrat and Puerto Rico, the U.S. and Canada.  In short, the congress lived up to its name, unlike any green roof gathering to date!

Coffee break and a time to catch up with old friends!  Photo Source and Courtesy: IGRA.

IGRA 2009: Program (May 25-27, 2009)

In the classic tradition of European conferences, the K3N Stadthalle in Nürtingen was an elegant and perfect-sized venue for the congress.  Comfortable conference rooms and excellent catering set the atmosphere indoors, while the neighbouring park and terrace café made fresh air a nice treat.

On May 25th, IGRA offered two excursions for the experientially inclined.  Both excursions were booked out, with 70 people touring Stuttgart region (in a double-decker bus) and 50 people visiting projects along the Rhine to the German solar capital, Freiburg.  A perfectly sunny day (perhaps even a tad hot) blessed the excursions, as the following two days of presentations would present thunder storms and cooler temperatures.

One of many green roof/ solar installations in Freiburg.

That evening, all congress participants united for a catered reception hosted by the Mayor of Nürtingen. The Kreuzkirche, a church renovated in the 1980s and since used for cultural events, is associated with the K3N town hall across the park.  Welcoming speeches were made by the Mayor, IGRA president Roland Appl, and by President of the German Roof Gardener Association (DDV), Reimer Meier.

The Congress Venue, the K3N:
Kunst. Kultur. Kongresse. Nürtingen;

The Kreuzkirche; Photo:

The congress took full advantage of the facilities at K3N (Kunst. Kultur. Kongresse. Nürtingen), with a big hall hosting the sessions on green roof architecture, and two smaller conference rooms for concurrent workshops: policy measures, and planning/ installation.  Simultaneous translation was available for all sessions with special headsets (while adrenaline-pumped translators steamed up their booths at the back of the hall).

Congress participants.

Session: Green Roof Architecture

The Green Roof Architecture presentations introduced successful and idealistic realizations of living architecture, whetting participants’ appetites and boosting the creative enthusiasm in the room to a nearly perceptible buzz.  Indeed, perhaps as a blinking bumblebee perceives its first flowering meadow of spring, the diversity of projects was so abundant and colourful that intellectual and creative thirsts were quenched to euphoric bliss.

Emilio Ambasz, acknowledged pioneer in the field of green architecture, inspired the audience with his concept “The Green over the Grey.”  Photo Source and Courtesy: IGRA.

A masterpiece of green roof architecture: Fukuoka Prefectural International Hall (ACROS) in Japan. Photo Source: IGRA,
Courtesy: Hiromi Watanabe.

The unique visions of architect Emilio Ambasz, accompanied by his own fables, made not only for a poetic presentation but also a dreamy keynote later that evening.  From Copenhagen, the Mountain Dwellings, which “combine the splendours of the suburban backyard with the social intensity of urban density,” has won many awards including “world’s best residential building.”  Other stunning projects included FiftyTwo Degrees in Nijmegen, Fusionopolis in Singapore, Zaragoza’s International Exhibition, California Academy of Sciences, and many more.  Experts on passive house design and solar building design  illuminated the abundance of solar energy that is freely available.

Workshop: An international comparison of funding and support for green roofs

Congress participants broke into two groups for the afternoon of day 1.  In the policy meeting, municipal representatives from various cities presented their programs, experiences and lessons with regards to green roof support and programming. German cities included Düsseldorf, Karlsruhe, Stuttgart, Munich, and Berlin, while international representation from Linz (Austria), London (UK), Portland (USA), and Copenhagen (Denmark) rounded the session off.  Lively discussions were enhanced by an unexpected power outage caused by a thunder storm.

Workshop: Planning, Installation and Maintenance

With input from experts each certified with lifetimes’ worth of practical experience, this workshop covered the basics with regards to green roof planning, installation and maintenance.  From the essential basics on waterproofing, to tips in plant selection, the workshop also granted essential plant information from a nursery, as well as installation and maintenance experiences from Germany and the Netherlands.

IGRA Awards 2009

For exemplary municipal engagement in promoting green roofs, the cities of Düsseldorf and Copenhagen received the IGRA Municipality Award. As the first large German city to conduct a comprehensive mapping program for green roofs, Düsseldorf has identified more than 730,000 m² green roofs.  Read more about this in Katja Holzmüller’s article "Climate protection, naturally – green roofs in Düsseldorf: financial support and quantitative analysis of aerial photographs."  Dorthe Rømø received this same award for Copenhagen, for having introduced green roofs as a new initiative with opportunistic basis in the momentum from the upcoming UN Climate Change Conference, which will be hosted in the Danish capital in December 2009.

Ho Wan Weng, Managing Director of ZinCo Singapore Ltd and green roof consultant of the project “Fusionopolis Phase 1” received the IGRA Award on behalf of the JTC Corporation; Photo Source and Courtesy: IGRA.

The roof gardens of Fusionopolis serve as the green lungs and social pockets for the office and lab staff; Photo Source: IGRA;
Courtesy: ZinCo Singapore Ltd.

For the IGRA Architecture/ Construction Award, architecture firm Donnig + Unterstab of Rastatt was distinguished for establishing a new model for school buildings: a passive house design, this school in Neckargemünd features an extensive green roof and three large-scale photovoltaic facilities.  From Singapore, Jurong Town Corporation (JTC) was also distinguished for its project “Fusionopolis” which features intensive green roofs on the 5th, the 17th/ 18th and the 21st/ 22nd floors, with the highest roof garden at approximately 80 m altitude.

Zeppelin Excursion

In his forward, the patron of the 2nd International Green Roof Congress, Wolfgang Tiefensee (Federal Minister of Transport, Building and Urban Affairs) stated that “The way in which we design our cities plays a key role in making our society sustainable.”  The vision of human activities in harmony with nature may seem like a dream of the future to many.  On the very last day of the congress, however, IGRA demonstrated the living truth of this vision.  On May 28, 2009, from the quiet levitation of a Zeppelin, the congress’ final green roof excursion showed how urban districts with green roofs can blend into the surrounding landscape.

Our Zeppelin Route from Friedrichshafen to Ravensburg; Image Source: Google.

At a consistent altitude of 300 m, a happy group of green roof professionals (max. 12/ flight) floated quietly above the idyllic patchwork landscape of Lake Constance’s north shore.  Of the panorama windows inside the gondola, several are operable to permit photography without Plexiglas scrapes or glare.  In fact, Zeppelins have been used for the special niche for aerial photography since the early 1930s.  Research missions of difficult and/ or vast landscapes (like the Arctic or great deserts) benefit tremendously from the excellent maneuverability and propulsion of airships, not to mention minimal vibration, quiet propellers and a gondola with great layout flexibility.

Our Zeppelin showed us a green world from above.

Back in 1895, Count Ferdinand von Zeppelin received Patent No. 98580 for the first “dirigible airship with several lifting bodies arranged in series bow-to-stern.”  His Luftschiffbau Zeppelin GmbH, established in 1908, still exists today; one of its subsidiaries, Luftfahrzeug Motorenbau GmbH, was the precursor of Maybach Motorenbau GmbH, today’s MTU.  At the height of its popularity, in 1929 the LZ 127 embarked on a round-the-world trip with four stopovers (Tokyo, Los Angeles, Lakehurst NY, and Friedrichshafen, Germany).  During the 1930s, the LZ 127 offered very popular and constantly booked out passages from Europe to South America.  Before the tragic Hindenburg accident in 1937 in Lakehurst NY, the LZ 127 had traveled 590 accident-free trips covering a total of 1,700,000 km.

Unlike its technological forefather from the adventuresome turn of the century, the Zeppelin NT (New Technology) is filled with non-flammable helium, and has powerful engines with swiveling propellers, state-of-the-art avionics and fly-by-wire flight controls which enable maneuvers similar to those of helicopters.  The rigid framework of the Zeppelin NT, also different from the original design, comprises triangular carbon-fibre frames and three aluminum longerons braced by aramide cables.  All the main components of the airship, including gondola, empennage and engines, are mounted on this rigid structure.

Flying high above the North Shore of Lake Constance.

This excursion was peaceful yet exciting at the same time.  Passenger exchange is carried out as a dynamic balancing act: while the Zeppelin sits lightly on the ground, its tail moving in whichever direction the prevailing winds push it, two passengers quickly disembark so that 2 new passengers can board.  Once in flight, the landscape below is close enough to physically sense its different qualities (e.g. air quality of forest vs. town vs. shopping centre) yet far enough for the “model” effect, where cars look like toys and people like ants.  Along the route from Friedrichshafen to Ravensburg, we passed over orchards, forests, farms, towns, shopping centres, etc.  We saw residential developments that have been entirely covered with green roofs, or which were built in the 1970s or 1980s and are being renovated one green roof at a time.

In Summary

Overall, this 2nd International Green Roof Congress was a tremendous success (see the International Green Roof Congress 2009 "Green Roof Visions Perfectly Transferred" Press Release here).  The program and quality of participation aside, its organization was excellent, from flawless excursions to secure coat check.  For participants staying near Stuttgart airport, an awkward location for public transit, the congress kindly arranged a special shuttle service.  The food was also very good, even for the vegetarian audience (which is remarkable in this land of meat and potatoes): many Swabian specialties were complemented by nice salad buffets (including asparagus cocktails!), beautiful dessert spreads, and lots of fresh fruit and juices throughout the day.  From the ubiquitous logo, it was clear that the event’s biggest sponsor was ZinCo GmbH, and the majority of presenters used ZinCo systems for their projects.  Nevertheless, any exclusivity or specific jargon could be easily tuned out given so many other superlatives comprising the event.

The proceedings from this congress are stunning not only in the thoroughness of documentation (all papers available in full length, English or German), but also in the quality of the colour print and binding.  Proceedings are available under, specifically here, for €39.80 plus shipping and handling (ISBN 978-3-9812978-1-2).

For green roof professionals, such conferences strengthen our sense of community, enhance our knowledge, connect people, refresh our visions, and sometimes even present magical glimpses of those visions manifest.  The vision of a world which, from above, is covered with photosynthesizing plants and solar energy harvesters may be inspiration enough.

Now consider the proof from the IGRA congress that so many and various interest groups and sectors agree with this shared vision; moreover that the idea of rooftop greening is so effectively spreading to other parts of the world!  I would hazard to guess that all 270 participants from the 2nd IGRA congress returned home inspired, motivated, encouraged, and stoked to be part of this exciting movement.

Please drop us a line below with your comments!

Greenroofs aside, in Nürtingen you can stroll along the Neckar River or visit narrow alleys with medieval backdrops
and picturesque corners.  Photo Source: Wikipedia.

Christine Thüring

Christine Thüring is the Student Editor and Principal of Chlorophyllocity.  See more of "Christine's Ramblings."

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