Top-down demolition allows for skyscrapers and other buildings to be slowly dismantled without disturbing the surrounding area. Taisei’s Ecological Reproduction System (Tecorep) is a process where a building is capped and each floor systematically disassembled level by level in order to recycle intact materials. The process restricts all the work within the building, which decreses dust by up to 90% and reduces construction noise by 20 decibels.
At each stage of demolition, each building floor has a temporary column set up that goes through several floors at once. The top floor structure of the existing building stays supported while the sub floors are systematically dismantled and jacked down after the floor is completely cleared. As it jacks down, the building cap lowers, as if eating the building layer by layer.
The first building to be taken down in this manner was the The Grand Prince Hotel Akasaka, a Tokyo landmark and the tallest building dismantled in Japan. This demolition system was debuted at the CTBUH (Council on Tall Buildings and Urban Habitat) 2012 9th World Congress by Makoto Kayashimara, manager of the Taisei Corporation. In an interview with Japan Times, Taisei’s construction technology developer Hideki Ichihara said most skyscrapers over 100 meters are torn down after 30 or 40 years and 99 Japanese buildings are set to be torn down in the next two years.
The video below shows a time lapse of the hotel’s deconstruction, as it would normally go unnoticed day by day until a significant portion of the building was missing.
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Implementing this process worldwide would result in cleaner building developments and lessen the impact on urban traffic. Observing the meticulous way that each floor of a building is jacked up, supported and gradually lowered, we can infer that creating a building, in similar fashion, would work in much the same way. If we take this further we could even see a time where buildings can pop up and tear down within the span of a few days, or even become retractable. This would be beneficial in setting up sites and being able to relocate for security purposes. The ability to move whole sections of cities would be akin to striking a theater production set.