The "World’s Tallest Tower" may be the greenest

When most super-tall skyscrapers are built, they are the crown jewels of the skylines in each city – acting like an exclamation mark on their perceived world status. With a newly proposed tower that is scheduled to begin this month in China, the skyscraper itself will be the skyline.

The developer, Broad Sustainable Building, says it plans to start construction on a 220-story prefab skyscraper, called SkyCity, that will reach 2,749 feet, which would edge out Dubai’s Burj Khalifa tower (2,717 feet) as the world’s tallest building. Theprefab, modular methods by which it will be built, along with the high urban densityit will provide, may make it one of the greenest towers ever built as well.

A monumental perspective of China’s proposed modular SkyCity tower. Image via Broad Sustainable Building.

According to the builders, the 220 stories, made of thousands of prefab modules, are expected to be assembled in the city of Changsha in an astonishing seven months. With another three months added for the construction of the prefab sections, the tower could be completed as early as the spring of 2014, if all goes well.

A view of the planned 2,749-foot-tall SkyCity as it would look on its proposed site. Image via Broad Sustainable Building.

Once completed, the building will be a city unto itself, providing a vertical, extremely dense urban environment for 30,000 people, using just 10 percent of the area that would normally be developed for a city of that size. Besides the usual office and retail space, plans for SkyCity’s interior also call for residential units for 4,450 families, organic farms, recreation areas, schools for 4,600 children, a hospital and other health care facilities.

To give a sense of scale, this is SkyCity as it would look if superimposed on the Chicago skyline. Image via Broad Sustainable Building.

The area surrounding the tower will also be a wide ring of parkland and trees, ensuring that residents of SkyCity will have access to the outdoors. On each of the tower’s many stepped terraces, green-roof gardens are planned, as well as an open-air park near the top of the tower, just below the crowning spire.

Some of the green roof terraces that are planned for the SkyCity tower. Image via Broad Sustainable Building.

By prefabricating each unit on the ground, Broad plans to dramatically reduce waste during the construction process and speed up the timetable. Each will include 8-inch-thick insulated walls, triple-glazed windows and exterior shading that are expected reduce the need for cooling by 30 percent. A cogeneration system will also capture excess heat from the power generation plant and redirect it for heating and cooling. Broad also claims that SkyCity can survive the punishment of a magnitude 9 earthquake and will have a three-hour fire-resistance rating.

The 92 elevators that will be used throughout the building will use low-energy cars. For those interested in severe fitness regimens, there will also be a continuous ramp, measuring six spiraling miles, all the way to the 170th floor.

* Randy Woods, EarthTechling