This morning the architect released the first images of his concept for the 45-storey building, close to the Tower of London.
The 'visually striking' 192m-tall tower incorporates nearly 85,000m 2of office accommodation and 1,000m 2of retail space.
According to developer Land Securities, the redevelopment of the City of London's 20 Fenchurch Street 'inverts the traditional deployment of the building volume'.
The scheme features larger floorplates at its top to exploit panoramic views across the capital.
Managing director of Land Securities' London portfolio Mike Hussey said: '20 Fenchurch Street is a rare opportunity to replace a dated building with a scheme of exceptional quality designed by a world-class architect.
'The design will enhance the skyline, the local streetscape and the emerging cluster of tall buildings in the City.'