WHAT architecture - London


Twin tower office building
Scale123000 sqm
Location127 Fitzwilliam Street, Sydney, New South Wales, Australia
ClientNew South Wales Government
Budget€ 400000000
DensityFloor Area Ratio of 25.6:1 (123000sqm GIFA vs 4800 sqm site)
Design Year2013




In the modern city, skyscrapers have emerged as the triangulation of political

will, economic prosperity and technological progress. What intrigues us in the

proposition for twin towers for Parramatta is not the triumph of building high

but the potential to create a specific identity for the city. A landmark that can

embody the creativity of its citizens.

So what are the critical parameters WHAT_architecture assigns to the design of

a high rise office?

ECONOMY: Given the spatial requirements of gross internal floor area, two

twin rectilinear towers were massed as simple rectilinear vertical extrusions

clad in glass. In doing so we are adopting forms that are efficient in

maximising the ratio of net lettable to gross floor area and that minimize the

area of external envelope in relation to lettable floor. This also allows for

quickness in construction.

STRUCTURE: Above a certain height, tall buildings are influenced more by

wind loadings than gravity. So as to reduce sway, we recognised that the

structural height (vertical cantilever) of the towers could be reduced by staying

the towers into a X-formation/

PLACEMAKING: The space between the legs creates enhanced public realm –

an arch – which accentuates urban circulation and thus the building form

provides both openness and enclosure. Facets at the lower levels demarcate

the entry points.

LIGHT: The X-form however is hybridised with the insertion of a bridge which

provides for greater natural daylight penetration into the interior tower spaces.

Views and daylight are further enhanced by facetting the corners to the upper


Parramatta is at the centre of the fastest growing region in Australia and with

this proposal we have a unique singular yet twinned tower. X marks this spot.