Construction of the Burj Khalifa began in 2004, with the exterior completed in 2009. The primary structure is reinforced concrete. The building was opened in 2010 as part of a new development called Downtown Dubai. It is designed to be the centerpiece of large-scale, mixed-use development. The decision to build the building is reportedly based on the government's decision to diversify from an oil-based economy, and for Dubai to gain international recognition.