The UN City in Copenhagen, Denmark consists of two campuses and is currently the sixth largest UN campus of the world, measured by the number of employees. The Danish architecture firm 3XN designed the magnificent, star-shaped building complex along the warehouse. High security and accessibility standards were taken seriously because the challenge for UN building is to provide safe working environment, and at the same time to create an open and welcoming atmosphere for the visitors. The project lasted 11 years from the planning phase in 2002 until the completion in 2013.

The building is located on an artificial island, and Campus 1 accommodates United Nations staff members from 11 agencies. With 45,000 m2 office space and 7,000 m2 basement, the building can provide a room for more than 1,500 employees. The design team kept the focus on sustainability and environmental friendliness, and the calculated energy consumption for the Campus 1 building was possible to plan to be less than 50 kWh/m2/year. The building is cooled by pumping seawater into the cooling system, and more than 1,400 solar panels are lining the roof to support the goal of generating renewable energy onsite. Also, the whole roof is coated with a white, recyclable membrane, made from plant-based materials, which reflects sunlight helping to reduce solar warming.

European Commission has awarded UN City with the Green Building Award for New Buildings, and it also holds LEED's Platinum-certificate. Participation in LEED (Leadership in Energy and Environmental Design) ensured that sustainability was integrated into the project since the beginning. 3XN and the contractor Pihl developed a facade cladding of white perforated aluminum shutters specifically for UN City. The facade is divided into three meter long modules, and shutters are designed to ensure solar shading without blocking the view. The employees can control the shades from their computers. The challenging shape of the building provided Rostek a unique possibility to offer tailor-made solutions for the life-long maintenance purposes of the UN City. The old maintenance box ladders wanted to be removed from facades and change them to the ideal solution, which would be safe but at the same time, the system was blended in with the building design.

The solution was to design white traversing masts to travel along the existing tracks and to deliver custom made self-hoisting platforms which are removable from the masts. The traversing masts blend in entirely with the white colored facade, and all 5 BMU units can be removed and stored out of sight when not needed for maintenance or facade cleaning. All the baskets are custom made and suitable for two persons to use at the same time moving vertically. One of the suspended platforms is 4 meters long, where two traversing masts are running the unit horizontally. With the remote control box, there is a possibility to control BMU from the rooftop as well.