When it comes time for an aging skyscraper to be put out to pasture, it's best to do so slowly. For buildings higher than 100 meters tall, there's no easy path to demolition. Sure, you could blow it up, but the cleanup would be brutal. You could slam it with a wrecking ball, but that's a little heavy-handed, don't you think?
Taisei Corporation, a Japanese construction company, is doing things a little more subtly, and making skyscraper deconstruction a more eco-friendly endeavor in the process.
Through their Ecological Reproduction System (Tecorep), rather than using cranes to take the building apart from the outside, they start from the inside, taking the structure apart floor by floor from the top down. A crane inside the building lowers materials harvested from each floor to ground level, generating electricity to power other equipment in the process. So with Tecorep, higher buildings are actually an advantage, since the crane can generate more electricity lowering materials over longer distances.
When a floor is completely stripped, the temporary columns and jacks holding it up are lowered, giving the building the outside appearance of shrinking into itself. Between salvaging reusable material and powering the project with clean energy, Tecorep reduces carbon emissions by 85 percent, according to the company. And because the demolition takes place within the building, it reduces noise and dust.
The method successfully brought down the Grand Prince Hotel Akasaka in Tokyo, the tallest building torn down in Japan to date. Hideki Ichihara, who runs Taisei's construction technology development, told the Japan Times that most skyscrapers over 100 meters are torn down after 30 or 40 years, and with 99 Japanese buildings set to fit that bill in the next 10 years, innovative deconstruction technology is an emerging field. Other corporations have been developing their own methods, such as the Kajima Corporation, which dismantles and lowers the building from the bottom up.
You can see Tecorep in action below.