The towers were designed by Argentinian architect César Pelli. They chose a distinctive postmodern style to create a 21st century icon for Kuala Lumpur. Planning on the Petronas Towers started on 1 January 1992 and included rigorous tests and simulations of wind and structural loads on the design. Seven years of construction followed, beginning on 1 March 1993 with the excavation, which involved moving 500 truckloads of earth every night to dig down 30 metres (98 ft) below the surface.
The next stage was the single largest and longest concrete pour in Malaysian history. 13,200 cubic metres (470,000 cu ft) of concrete was continuously poured through a period of 54 hours for each tower. This record-breaking slab with 104 piles forms the foundation for each tower.
From this floor rose a 21-metre high retaining wall, with a perimeter length of over 1,000 metres (3,300 ft). This concrete shell and the basement area it enclosed required two years to complete, and up to 40 workers on site 24 hours per day.
The Petronas Towers feature a diamond-faceted facade consisting of 83,500 square metres (899,000 sq ft) of stainless steel extrusions. In addition, a 33,000-panel curtain wall cladding system resides within the towers. While the stainless steel element of the towers entices the illustrious sun, highlighting the magnificent towers, they are composed of 55,000 square metres (590,000 sq ft) of 20.38-millimetre (0.802 in) laminated glass to reduce heat by reflecting harmful UV rays.