Tomorrow’s Construction Already a Reality: Inverted green roof for office building on the EUREF Campus

Sustainability is much more than just a trend. Especially in the construction industry, projects that harmonize ecological, economic and social aspects in planning, construction and operation are no longer pie in the sky dreams: rather, more and more of them are being realized every day.

The EUREF Campus in Berlin-Schöneberg is a model project for the energy revolution unlike any other in Europe. The EUREF Campus 14 office building is an architectonic highlight of the grounds, with outstanding energy efficiency – sustainable from the base of the building up to the green roof construction with the JACKODUR® thermal insulation system for inverted roofs.

The gasometer in Schöneberg is one of Berlin’s best-known landmarks. On the 5.5-hectare grounds of what was once the GASAG industrial complex, an ultra-modern urban district has been under construction since 2008. It shows how the planned energy revolution can succeed. According to project developer EUREF AG, the Campus has been meeting the German federal government’s CO2 climate objectives for 2050 already since 2014. A nearly climate-neutral energy supply, the intelligent energy grid, and highly efficient buildings are the key components of the innovative concept. The photovoltaic systems, wind turbines and biogas-fired combined heat and power plant installed on the grounds generate most of the total energy required there.

The EUREF Campus features a wide range of special buildings and styles.

Alongside listed, painstakingly renovated historic structures, attractive new buildings that satisfy the most contemporary architectural demands are being erected. Economically advanced buildings that can last for generations and conserve valuable resources during their construction and operation while offering their users a comfortable working space that complies with the principles of sustainable building.

The EUREF Campus 14 office building is one of the new buildings on the grounds. It was completed in December 2015. The facade of the tower reflects the shapes and lines of the gasometer as well as a vertical wind turbine and harmonizes superbly with its surroundings. The interior of the structure and the materials used are designed from maximum efficiency: Its building services and energy concept make it a high-performance building. The thermo-active building system for the regulation of heating and cooling, centrally controlled blinds on the triple glazed windows and automated lighting provide a high level of comfort and a good indoor climate. And the building’s insulation is also a major factor, whereby the roof construction of EUREF Campus 14 particularly stands out: planners, architect and roofing company opted for the inverted roof method with JACKODUR® thermal insulation boards.

The inverted roof is an invented flat roof where the thermal insulation – unlike with the conventional arrangement – lies on top of the roof membrane and is thereby exposed to the weather.

Though this might seem out of the ordinary at first, it offers a big advantage: the insulation layer provides the membrane with effective and durable protection against mechanical damage, UV embrittlement and extreme temperature fluctuations. However, the insulation itself must also withstand them. With JACKODUR® insulation boards, JACKON Insulation supplies the ideal products for inverted roof applications. Made of extruded polystyrene foam (XPS), JACKODUR® thermal insulation boards have a closed-cell structure that makes them insensitive to moisture and maintains their compressive strength and dimensional stability even under high loads. Mani Pentschew, design consultant for JACKON Insulation, describes one of the special features of the EUREF roof: “With a building height of about 32 meters, the EUREF Campus 14 is classified as a high-rise, so the roof design requires special measures to secure it against wind suction. Subject to those conditions, implementing the inverted roof configuration in an ideal manner was a challenge – but one that the roofer was able to overcome very well with our products.”

To that end, the inverted roof was constructed in multiple layers. The roof’s load-bearing structure and root-resistant membrane were covered with JACKODUR® KF 300 Standard SF in a thickness of 240 mm. Ralf Logsch, Construction Manager at SKD Bau, the roofing company contracted for the job, justified the choice of JACKODUR® this way: “The boards can be installed easily and quickly, so it wasn’t hard to fit them along all of the curves of the oval roof layout. We installed the roof during the fall and winter months at the end of 2014 and early 2015. Because XPS is weather-proof, we were able to work under nearly all weather conditions. And the insulation loses none of its properties over time due to heavy rains or alternation between frozen and thawed states.” In order to impart the necessary load and prevent drifting, grass pavers were laid on the insulation boards and filled with coarse gravel. The green roof installation used a system from Optigrün. The planting itself was installed by rolling out prefabricated vegetation mats planted with sedum. This kind of extensive planting requires very little maintenance and remains permanently green. The accessible areas of the roof were filled in with a gravel bedding layer and covered with pavers. As a result, the inverted roof construction method is not only functional, but also contributes visually to the value of the building.

The high quality of the overall building is certified by, among other things, the Platinum rating level LEED certificate for EUREF Campus 14.

LEED (Leadership in Energy and Environmental Design) is the most widely used green building rating system in the world. Where Environmental Product Declarations – or EPDs for short – are available for a certain quantity of the construction products used, this has a positive effect on the rating. Here, too, JACKODUR® was able to provide impressive results, because JACKON Insulation has obtained several EPDs for its XPS boards. Using eco-balance sheets, EPDs render the environmental impacts of products transparent, thereby making it much easier to calculate the ecological sustainability of a building.

The building’s tenant is DB Engineering & Consulting, the engineering and consulting firm of Deutsche Bahn, which works on the development and implementation of mobility and transport solutions. The company has joined the ranks of the more than 100 start-ups, global players and research institutions that are making the EUREF Campus into an innovative center for the energy revolution. As the project development continues, even more office space, residential units, restaurants and event facilities are being built. In some 15 building complexes, nearly 6,000 people will then be able to work and carry out research. The prospect pleases design consultant Mani Pentschew: “The use of our JACKODUR® products in such a pioneering project is something quite special and a great project for JACKON Insulation.”

Property data:

  • EUREF Campus 14, office building
  • 10829 Berlin, Germany
  • Building height: approx. 32 m
  • Floor space: approx. 7,000 m²
  • Architecture and construction management: EUREF Consulting GmbH, Berlin
  • General contractor: Wolff & Müller GmbH & Co. KG, Berlin
  • Roofing Company: SKD Bau GmbH, Göda
  • The material used: approx. 650 m² JACKODUR® KF 300 Standard SF, 240 mm