Platinum and diamond: Kö-Bogen II receives the highest DGNB certifications

The Kö-Bogen II office and commercial building in Düsseldorf stands out for more than just having Europe's largest green façade: in addition to the platinum DGNB certificate, the Kö-Bogen II even received a DGNB diamond rating, the only one of its kind in the world and a brilliant success – for the building and for the environment.The Kö-Bogen II sustainability project shows how it's done.

Forward-thinking: green building

Kö-Bogen II

Platinum and diamond DGNB certificate for the Kö-Bogen II © Jürgen Biniasch / GEZE GmbH

Sustainable building is becoming more and more important to reduce the environmental impacts of the construction industry.After all, the building and construction sector is responsible for around 30 % of greenhouse gas emissions.Because of this, more and more building owners and investors are becoming interested in environmentally-friendly and sustainable buildings and building projects, so-called green buildings.


Internationally recognised: DGNB certifications for sustainable buildings

The German Sustainable Building Council (DGNB) assesses building sustainability.DGNB certification can vary depending on the level the project wants to attain (gold, silver, bronze, platinum) and the building category (new construction, existing building, district).DGNB certifications are recognised in particular in Germany, as well as internationally.An independent audit ensures that buildings meet the strict criteria of the DGNB.

Documentation and testing essential to a successful DGNB certification

In order to ensure that the criteria necessary for DGNB certification are fulfilled, it is important that everyone involved – including architects, engineers, building owners, specialist planners and other trades – work together closely.Ultimately, detailed verification of all implemented measures and their impacts is required to receive the DGNB certification. 

  • Sustainability: the primary goal of DGNB certification is evaluating and ensuring the ecological, social and economic sustainability of a building.
  • Energy efficiency: the building should use as little energy as possible, and ideally make use of renewable energy sources.
  • Environmental protection: environmental aspects like water consumption, waste management, and reducing harmful emissions must be taken into consideration.Using rain water and separating waste are examples of the kinds of measures that are encouraged.
  • Health and comfort: this includes good air quality, appropriate lighting, and acoustic comfort for building users.
  • Space optimisation: it is important to ensure that available space is used in a smart way.
  • Building ecology: the origins of building materials and their environmental impacts are analysed.Sustainable materials and ecological construction methods are encouraged.
  • Innovation: integrating innovative technologies and concepts that contribute to sustainability is viewed in a positive light.
  • Life cycle assessment: the life cycle costs and impacts of the building are important.This includes not only the construction costs, but also operating and maintenance costs throughout the entire service life of the building.
  • Mobility and transit access: good access to public transportation and bicycle parking can be bonus points in the assessment.
  • Social responsibility: the building's impacts on the local community, for instance how the building supports the local economy and promotes social interaction, are taken into consideration.

In addition to its high importance to the urban design of Düsseldorf, the K II's architecture will remain a standard for new construction projects into the future, particularly with respect to wise use of resources and environmental protection”.

Stephan Deußer, Project Manager, B&L Group

Sustainable solutions for successful DGNB certification

The DGNB views the integration of innovative technologies and concepts that contribute to sustainability in a positive light.No wonder that door technology from GEZE was used in the Kö-Bogen II sustainability project.Many of our products meet the sustainability requirements of leading global green building assessment systems, such as those defined by the DGNB and LEED.We conform to these requirements voluntarily and transparently by providing environmental product declarations (EPDs) for our products. In addition, our products are listed in the online databases DGNB Navigator and, with their respective certificates.The certificates certify the number of points with which a GEZE product can contribute to the successful DGNB or LEED certification of a building, so

Green and inclined façade – a challenge for door technology

Slimdrive SL NT-FR

Customised door technology: the GEZE Slimdrive SL NT-FR. © Jürgen Biniasch / GEZE GmbH

Slimdrive SL NT-FR

Entrances to stores and offices were designed to be visually appealing with the narrow sliding door system. © Jürgen Biniasch / GEZE GmbH

The complex and challenging installation situation represented a challenge for sliding and swing door drives in the green façade, which is partially tilted and covered in hornbeams.Due to the very low drive height of just 7 cm, our Slimdrive sliding door systems were the perfect choice: with their low installation height, they blend in harmoniously with the green façade. 

  • The Slimdrive SLV was designed for building-specific planning on angled façades or corners, such as on pavilions, underground garage and restaurant entrances. It was manufactured with the right angle of drive rail for the building.
  • The Slimdrive SL NT-FR with escape route function is used in escape and rescue routes.
  • Another benefit in terms of sustainability is that the Slimdrive door system efficiently extends its service life with a very smooth-running, low-wear direct current drive and a self-cleaning roller carriage.Independent error detection and logging also reduce maintenance requirements.This saves resources.

Special solutions for closing edge protection for the green and inclined façade

Slimdrive SLV

The proven sliding door system from GEZE guarantees protection and offers a night-time closer function, despite the angled design of the façade. © Jürgen Biniasch / GEZE GmbH

In addition, we were able to ensure the specified protection of the secondary closing edges on the angled façade with special solutions.The distance between the protective leaf and façade was so great that there was a danger children, for instance, could get between the protective leaf and the façade.   Our solution? Specially planned and manufactured glass or sheet metal panels for closing edge protection.This required intensive collaboration between GEZE project consultants and planning and object protection, as well as other trades.

In an ambitious project like the Kö-Bogen II, it is essential for all trades to work together well right from the planning stage.GEZE made an important contribution to developing the right, building-specific solutions, as well as interdisciplinary planning and implementation.

Wolfgang Faßbender, Architectural and project consultant at GEZE

Planning consultation and maintenance throughout the entire project life cycle

Detailed verifications of the implemented measures and their impacts are essential for successful DGNB certification.Because of this, reliable and competent planning support and handling from a single source are a major advantage.Our experts offer you individual consulting and comprehensive services, from planning to installation, to maintenance and disassembly if necessary. 

Important factors in certifications of sustainable building projects

Many building projects work to attain certifications, as sustainability certificates are often required for grants of public funds, such as KfW grants.Michael Halstenberg, attorney and former Ministerial Director, and Günther Weizenhöfer, Architect and Team Lead Pre Sales Development, discuss current developments and potential difficulties related to liability in case of a defect.

We support you in your planning