China
China's Ministry of Housing and Urban-Rural Development and Ministry of Emergency Management announce in a joint statement that cities with a population of more than three million people are not allowed to construct skyscrapers taller than 500 m and need a special exemption in order to construct a building taller than 250 m. The ministries also announce that cities with a population of less than three million people are not allowed to construct skyscrapers taller than 250 m and need a special exemption in order to construct a building taller than 150 m.
Sources: BBC News