Key milestones in the story of the Petronas Twin Towers
From the initial design competition in 1991 through construction, inauguration, and beyond — every major milestone in the towers' remarkable story.
An international architectural competition is launched. Eight prestigious firms submit proposals for Malaysia's landmark tower project.
Official planning for the Petronas Twin Towers commences. The former Selangor Turf Club site in central Kuala Lumpur is selected.
Argentine-American architect César Pelli wins the design competition with his twin-tower concept featuring Islamic geometric floor plans.
Massive excavation begins, with 500 truckloads of earth removed nightly, digging 30 metres below the surface.
Geotechnical surveys reveal unstable limestone. The entire building footprint is moved 61 metres southeast to stable soft rock.
Bachy Soletanche bores 104 concrete piles per tower to depths of 60–114 metres, creating the world's deepest building foundations.
Construction of the reinforced concrete superstructure commences, with two competing teams racing to complete their respective towers.
The 750-tonne double-decker skybridge is pre-assembled on the ground before its dramatic lift to the 41st floor.
Interior fit-out of both towers is substantially completed, including the installation of 78 elevators and building management systems.
The iconic stainless steel pinnacles are installed atop both towers, bringing the total height to 451.9 metres.
Overall construction is declared complete at a total cost of approximately US$1.6 billion.
The first Petronas employees move into the towers, beginning the phased occupation of the building.
The Petronas Twin Towers officially claim the title of world's tallest buildings, surpassing Chicago's Sears Tower.
Prime Minister Mahathir Mohamad inaugurates the towers on Malaysia's 42nd Independence Day in a ceremony broadcast worldwide.
The towers receive the prestigious Aga Khan Award for Architecture, recognizing their contribution to Islamic architectural heritage.
Taipei 101 surpasses the Petronas Towers as the world's tallest building, though they remain the tallest twin towers.
Merdeka 118, also in Kuala Lumpur, surpasses the Petronas Towers as Malaysia's tallest building.