"Sky City One", touted as the tallest skyscraper of the world in the near future, is all set to break ground in June 2013, according to the Broad Sustainable Group, developers of the building. The Group announced in a statement that it has received all building permits and approvals to start construction on the 2749 meter high-rise and will complete building in 210 days. Sky City one is coming up in Changsha City in South China

The building, once completed, will be the tallest sky-scraper of the world. The current tallest building is Dubai's Burj Khalifa, measuring 2772 feet. However, Sky City will not only take over its "tallest building" title but also exceed the speed at which the Dubai structure was built. While the former was built in six years, the Sky City will only take seven months to be completed.

Usually, an average skyscraper takes around two to three years to complete, but this structure will only take approximately seven months to finish. Earlier, the Broad Group had claimed that they would complete the building within three months. However, the company now says that it will take some time more.

The Broad Group already has broken some construction speed records. The group completed a 3 story building in just nine days and a 30 story building in 15 days.

But how do they manage to build at such a fast pace?

The secret to Broad Group's rapid construction rate is "Prefabrication", where almost 95 percent of the building's needs are assembled beforehand in a modular form. Check out how the Sky City will be assembled in a graphic, here.

About Sky City One

Sky City One will be a one-of-a-kind, mixed use skyscraper, which will be a city in itself. Of the 220 stories, 83 percent of the building will be used for residential purposes and 3 percent for office usage. According to Treehugger.com, the building will accommodate around 4450 families in apartments measuring 645 square feet to 5000 square feet. It will also have around 10,000 square feet of school, hospital and office area.

The Broad Group claims that the skyscraper is a next-generation building and will be five times more energy efficient than a conventional energy-saving building. The structure will have 8-inch thick insulated and glazed walls and its exterior shading will save cooling expenses by 30 percent. A co-generation plant will supply the building with heating and cooling facilities using waste heat from power generation.

The building will be earth-quake resistant, able to withstand a '9 Richter Scale' magnitude quake. It will also have a three-hour fire resistance system. Moreover, since most of the amenities will be in the tower, it will save a lot of land space. In fact, the building takes up only 10 percent of the site, while the rest of the lot will be developed into parks and open recreation space.

Check out a video of the building plan, below:

While people around the world are mesmerized by the idea of "a city in a tower", some experts have called it "madness" and a "folly at its best". In an interview with Business Insider, Christian Sottile, the Dean of the School of Building Arts at the Savannah College of Art and Design said:

"Pre-fabrication has revolutionized the building industry - applying this now as a strategy for tall buildings under the right conditions is brilliant. The irony is that at the same time, if you look at the outcome of this endeavor urbanistically, it is at best a folly, and at worst, madness. The proposition that a city can be contained within one building is unnatural and devastating to the human spirit."