Unlike previous building trends of the 1980s and early 1990s, many high-rise buildings of the second boom are for residential use due to a surge in demand for luxury housing properties in Hong Kong. In addition, the closure of the Kai Tak Airport and the relaxation of height restrictions on the Kowloon Peninsula allowed many tall skyscrapers to rise in Kowloon, such as Sorrento, Langham Place Office Tower, and The Cullinan, all of which exceed . Skyscrapers also grew in the New Territories, such as the developments of Metro Town and LOHAS Park in Tseung Kwan O. However, proposals for large scale building projects slowed down considerably over the 2000s due to a heightened community awareness of skyscraper's effect on urban ecology, such as changes to air circulation (dubbed as "wall effect") and air pollution.