double floors / false ceilings) and constitute a big part of the regular maintenance required. Conveying systems Systems for transport of people within buildings: Elevator Escalator Moving sidewalk (horizontal and inclined) Systems for transport of people between interconnected buildings: Skyway Underground city Building damage Buildings may be damaged during the construction of the building or during maintenance. There are several other reasons behind building damage like accidents such as storms, explosions, subsidence caused by mining, water withdrawal or poor foundations and landslides. Buildings also may suffer from fire damage and flooding in special circumstances. They may also become dilapidated through lack of proper maintenance or alteration work improperly carried out. Hypothetical future buildings Advances in construction technology, ideologies, etc may allow (or necessitate) the construction of new kinds of buildings and complexes, like an arcology. See also Autonomous building Commercial modular construction Earthquake engineering Float glass Green building Hurricane-proof building List of buildings and structures List of largest buildings in the world List of tallest buildings in the world Natural building Natural disaster and earthquake Skyscraper Steel building Tent References External links