In the international competition for a new United Nations headquarters in Bonn (Germany), the proposal of XML was awarded an Honorable Mention. In collaboration with LOLA Landscape Architects and building consultancy firm ABT, XML made a design for a UN campus situated at the historic site were until 1999 the (West-)German parliament convened. Part of the plan is a new 14,000 m2 sustainable building for the UNFCCC, the part of the United Nations that is involved with international consultations about climate change, including the Kyoto protocol. 70 teams competed in the competition that spanned two phases. Following New York, Geneva and Vienna, the campus in Bonn will over time form the fourth place of the UN in the world.

The United Nations in Bonn currently occupies a series of existing buildings that were previously used by the German parliament. The competition brief called for a new building to be added to the existing facilities, as well as for a proposal for a landscape plan to connect the separate buildings into a coherent campus.

  
In the XML proposal, the requested program is divided over 13 floors above ground and 2 basement floors arranged in a compact square floor plan based on a 5.4 m x 5.4 m grid. This way, the program is organized within a generic and slim volume with a minimal footprint. The compact footprint relates to the scale of the existing buildings, which creates a campus composed of a series of detached buildings of comparable scales interconnected by landscape. A modification of the generic volume – placing the glass facades under an angle - gives the building an unexpected novel appearance. The transparent architecture of the proposal seeks a dialog with the tradition of the international style in which many UN buildings were designed (such as the UN-headquarters in New York and the Unesco offices in Paris) as well as with the modest, servient architecture of the existing buildings.

Providing sufficient cooling and comfortable lighting conditions are important challenges when designing an energy efficient office building. By placing the glass facades under an angle, direct sunlight is avoided in Summer, reducing the need for cooling. During the other half of the year the angled glass allows for sun access. Comparable to traffic towers at airports, the angled facade reduces glare, providing the office workers with unobstructed views of the surrounding landscapes.

The construction is composed of a central located core and columns placed along the facade to open up the office floors and providing a maximal freedom for office arrangements. The 5.4m x 5.4m grid is subdivided into a smaller grid of 1m35 x1m35. The application of floor plates with integrated structure and service shafts makes it possible to realize completely open floor plans, thus increasing the flexibility of the building.



Every level acts as a plate that can be freely arranged and over time easily adjusted to accommodate the altering needs of the occupant. This results in a building with an efficient generic floor plan that gives way for a multitude of office configurations and work styles, characteristic for the contemporary office culture of the UNFCCC that works a lot with altering teams.

  
By organizing the requested program in a slim tower every workspace has good lighting and a nice view, regardless of the chosen configuration of office spaces. The angled facades create terraces on which vegetation is planted. This way, every workspace is in the proximity of an outside garden. Closed office spaces, such as individual offices and meeting rooms, are organized to the south side of the building overlooking Bonn. The large open office floors for the teams are mainly situated on the north side of the building, giving unobstructed views towards the river Rhine.

  

For the planting of the connecting landscape all 193 UN member states will be invited to donate a plant. These plants will be analyzed for their most important characteristics. According to these characteristics the plants will be placed in the outside landscape or within the buildings on campus. For the interior spaces plants will be selected with specific functional qualities - for instance sound insulation, air purification or smell - to improve the working climate. Other plants might be selected for esthetic value like color, texture or form. Plants positioned in the campus landscape are organized along a time line representing the date on which the nation that has donated the plant joined the United Nations. Hence, this barcode of plants describes in a subtle way the birth and development of the United Nations.

The angled glass facades reflect the surrounding world landscape and the river Rhine. Here, the typical anonymous architecture of international institutions blends with the local context and biodiversity of the campus landscape of plants and trees from all over the world. The reflection of this context also changes the appearance of the building throughout the day: landscape and architecture mix in a continuous changing image of historic buildings, plants, air and water. A living history as a representation of sustainability.