Following their success in winning first prize in an international competition, the architects von Gerkan, Marg and Partners (gmp) have been commissioned to realize a tower block complex of ten buildings in Nanjing. The design by gmp is for a financial enterprise centre on a site of about 80,000 sq m in this large eastern Chinese metropolis. The above ground gross floor space of the 120m to 200m high tower blocks will be about 500,000 sq m.
A 14m wide river crosses the site to the north of the future financial centre; a 28m wide green belt runs through the development, which is served by an underground railway line. The design idea is based on the following features: the outer edges of the site are bounded by the buildings, providing generous space for green areas and footpaths in the clearly defined central area. The architects have arranged the tower blocks on the site in a windmill sail pattern arranged in a clockwise direction, creating an outer ring of seven 120m to 200m high, and an inner ring of three 130m to 150m high buildings.
The facade concept plays an important role in terms of the sustainability of the design, as it helps to conserve energy and to ensure the well-being of users: the facades of the outer buildings rely on the natural shading from vertical shading fins which are arranged in such a way that they prevent solar heat gain from the low sun positions in the east and west. Large window elements between the shading fins let in daylight from the north and south.
The three inner tower blocks use the principle of double-skin facades with counter sash windows featuring individually controllable solar screening which is protected from the weather and avoids the need of darkened solar protection glazing. This means that the offices do not require artificial lighting during the day, which conserves energy and protects the environment. The colour scheme of the facades is reminiscent of the Nanjing city wall. The dominant scheme is based on the different colour shades of burnt brick, and so each block is given its own identity with a different colouring.