As of my knowledge cutoff of September 2021, the top 5 tallest buildings in the world are:
1. Burj Khalifa - located in Dubai, United Arab Emirates, standing at 828 meters (2,716 feet) tall.
2. Shanghai Tower - located in Shanghai, China, standing at 632 meters (2,073 feet) tall.
3. Abraj Al Bait Clock Tower - located in Mecca, Saudi Arabia, standing at 601 meters (1,971 feet) tall.
4. Ping An Finance Center - located in Shenzhen, China, standing at 599 meters (1,965 feet) tall.
5. Lotte World Tower - located in Seoul, South Korea, standing at 555 meters (1,819 feet) tall.
Burj Khalifa
Burj Khalifa is currently the tallest building in the world, located in Dubai, United Arab Emirates. It stands at a height of 828 meters (2,716 feet) and has 163 floors. The construction of the building began in 2004 and was completed in 2010, with its official opening on January 4th, 2010.
Burj Khalifa has multiple uses, including offices, residential apartments, a hotel, restaurants, and observation decks. The observation deck, called At The Top, is located on the 124th floor and offers a stunning view of Dubai's skyline. There is also a higher observation deck called At The Top Sky, located on the 148th floor, which is the highest observation deck in the world.
The design of Burj Khalifa is inspired by the shape of the Hymenocallis flower, which is native to the region. The building features a Y-shaped plan that allows for maximum natural light and views of the surrounding areas. It also incorporates sustainable features such as a condensate collection system, which provides water for irrigation and other uses.
Shanghai Tower
Shanghai Tower is the second tallest building in the world, located in Shanghai, China. It stands at a height of 632 meters (2,073 feet) and has 128 floors. The construction of the building began in 2008 and was completed in 2015, with its official opening on February 22nd, 2016.
Shanghai Tower is a mixed-use building, which includes offices, hotels, retail space, and observation decks. The observation deck, called the Top of Shanghai, is located on the 118th floor and offers a panoramic view of the city. The building also features a unique double-skin facade that helps to reduce energy consumption by providing natural ventilation and insulation.
The design of Shanghai Tower is inspired by traditional Chinese architecture, such as the pagoda, and features a twisting form that tapers as it rises. The building also incorporates sustainable features such as rainwater harvesting, a greywater recycling system, and a highly efficient heating and cooling system.
Abraj Al Bait Clock Tower
Abraj Al Bait Clock Tower is the third tallest building in the world, located in Mecca, Saudi Arabia. It stands at a height of 601 meters (1,971 feet) and has 120 floors. The construction of the building began in 2004 and was completed in 2012, with its official opening on August 18th, 2012.
Abraj Al Bait Clock Tower is part of a larger complex that includes a hotel, residential apartments, and a shopping mall. The clock face on the tower is the largest in the world, measuring 43 meters (141 feet) in diameter. The building also features an observation deck on the 154th floor, which offers a panoramic view of the holy city of Mecca.
The design of Abraj Al Bait Clock Tower is inspired by traditional Islamic architecture, such as the nearby Masjid al-Haram mosque. The building incorporates sustainable features such as a cooling system that uses ice to reduce energy consumption, and a solar panel array that provides energy for the complex.
Ping An Finance Center
Ping An Finance Center is the fourth tallest building in the world, located in Shenzhen, China. It stands at a height of 599 meters (1,965 feet) and has 115 floors. The construction of the building began in 2009 and was completed in 2017, with its official opening on March 18th, 2018.
Ping An Finance Center is a mixed-use building that includes office space, a hotel, and retail space. The observation deck, called the Ping An Finance Center Observatory, is located on the 118th floor and offers a stunning view of the city. The building also features a unique façade system that helps to reduce solar heat gain and improve energy efficiency.
The design of Ping An Finance Center is inspired by traditional Chinese architecture, such as the taichi symbol. The building incorporates sustainable features such as rainwater harvesting, a greywater recycling system, and a highly efficient heating and cooling system. It is also equipped with a wind turbine that generates energy for the building.
Lotte World Tower
Lotte World Tower is the fifth tallest building in the world, located in Seoul, South Korea. It stands at a height of 555 meters (1,819 feet) and has 123 floors. The construction of the building began in 2011 and was completed in 2016, with its official opening on April 3rd, 2017.
Lotte World Tower is a mixed-use building that includes offices, a hotel, residential apartments, retail space, and an observation deck. The observation deck, called Seoul Sky, is located on the 118th floor and offers a panoramic view of the city. The building also features an underwater aquarium, called Lotte Aquarium, which is located on the basement levels.
The design of Lotte World Tower is inspired by traditional Korean art and culture, such as the curves of a traditional Korean celadon vase. The building incorporates sustainable features such as rainwater harvesting, a greywater recycling system, and an energy-efficient heating and cooling system. It is also equipped with a high-performance double-skin façade that helps to reduce energy consumption.