In 2001 Grimshaw achieved detailed planning consent for a 52 storey office tower containing 100,000 sq m of net office accommodation 400m from the Tower of London World Heritage Site without a planning inquiry. The site marks the eastern gateway to the City of London next to Aldgate underground station. It is outside the strategic views of St Pauls, not within a conservation area and does not contain listed buildings. It lies outside two of the three proposed viewing cones for the Tower of London, and whilst it falls inside the third, so do Swiss Re, 110 Bishopsgate, Tower 42 and the other towers of the existing and emerging City skyline.
The building design concept can be understood by imagining four “open books” standing with their spines erect facing one another. Their disposition across the site and variations in their height respond to the surrounding context. Eight sheer façade planes form the “book covers”. No two planes ever meet and none are parallel.
Corners are left open to reveal the individual sharpness and slenderness of each plane. Technically, each 1350mm deep zone accommodates the primary structural stability frame and a naturally ventilating glass façade. Visually each presents a subtle iridescent tableau, changing constantly on account of external climate conditions and internal patterns of work.
Four façade planes divide the site diagonally. They create a linear space that is broadest at its centre and narrower at its two ends. This serves as entrance hall below and atrium above. At each end it addresses a major pedestrian desire line from a mainline station. There are five different types of typical floor-plate and the triangular plan geometry is regularised internally by the positioning of escape stairs and cores. Consequently accommodation is of a uniform width and allows efficient space planning.
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