Kingdom tower is under construction at Jeddah, Saudi Arabia. The tower will be 1000 meters high, pushing Burj Khalifa to spot #2 (828 meters). The construction of the tower has been approved and because the soil conditions did not permit, the overall height of the tower had to be brought down from 1.6 km to under 1 km. The overall cost of construction is estimated to be about $1.23 billion. Here's a graphical comparison of the Kingdom Tower, Burj Khalifa and the rest. The tower will have 156 floors and the construction is expected to complete by the end of 2017. Structural engineering consultation is being provided by Thornton Tomasetti.