The WHO Headquarters site is currently defined by its bold integration of built form and landscape. While the UNAIDS building uses its permeable base to create a floating volume above the sloping ground plane, the main office runs parallel to a long ridge, acting as a massive retaining wall projecting out of the landscape.
Our primary objective is to strengthen this concept through the new extension. By rooting down into the ground, it establishes its own unique relationship to the landscape, while unifying a network of four green program nodes. The Entry Plaza connects the existing and new buildings, linking to a Memorial Garden that merges the existing large trees into the new landscape. This links to an Office Atrium that provides natural light and ventilation at the core of all eight office floors. Finally, a series of bioswales terrace down to a Wetland Park, purifying both building and storm water, while creating a natural habitat for local wildlife.The result is three buildings that establish a strong, physical connection to each other and conceptually unify the entire site through their complementary relationships to the surrounding landscape.
The focus on connectivity throughout the site extends into the new program elements as well, facilitating convenient access for WHO staff and creating flexible workspaces that can adapt to the dynamic needs of the organization. This starts at the critical juncture between the existing and new buildings with a large, transparent multi-purpose hall that bridges levels 0 and -1. The two levels of connection provide direct access to the conference centre and restaurant, as well as secured access to the offices and SHOC facility, creating a coherent flow through the buildings and maximizing both social and environmental interactions.
The office form is an evolution of the existing building’s massing. By offsetting the mass distribution both vertically and horizontally, a new proportion is created that complements the purity of the existing building without competing with its prominence. Tilting the axis of the southwestern facade increases the view angle from the existing building, provides greater southern exposure, and creates a geometry that integrates into the base volumes and landscape.
In addition to building orientation, a double skin curtain wall system promotes passive sustainability through ventilation, heat gain, and daylighting. The extensive green roof area further enhances the thermal performance of the building while geothermal and solar energy are collected in an effort to eliminate dependence on fossil fuel sources. The bioswale system for water filtration makes sustainability an active process that can be experienced on a daily basis by the building users.
