Prefabricated Construction Goes BIG

March 17, 2015

Prefabricated skyscraper Sky City in China

Up until now, prefabricated buildings and building sections have been used to build homes and other small structures.  In China, however, they are taking things BIG – constructing a skyscraper at the rate of three floors per day!

What is prefab?

Prefabricated construction, or prefab, involves constructing portions of a building (walls, wall sections, roofs, floors) off-site (usually indoors), then transporting those sections to the job site where they are assembled quickly into the finished building.

Prefab is green because it allows for more efficient use of building materials, prevents structures from getting wet before they are protected, and saves construction time.

Going BIG

Broad Sustainable Buildings is creating what it calls Sky City, which could potentially be the tallest building in the world (it started at 97 floors, and was cut due to a nearby airport).  It may not make that mark, but it is the tallest prefabricated building, for sure.  While that alone is enough to create news, the speed at which it is being built is the real story.

Prefabricated skyscraper Sky City in China

Sky City is an 800 apartment, 57 floor building in Changsha, China, that is located next to Broad’s factory.  The building provides offices for the company and homes for its workers.  The building is rising quickly, adding 3 floors each day.

How Do They Do It?

The building is made of prefabricated steel panels manufactured in a small town about 90 miles away.  The panels are transported to the plant next door, where they are assembled and wiring, plumbing, ventilation, sheet rock, and floor coverings are added.  Special spacers are attached to the assemblies, allowing them to be transported several at a time and acting as a lifting point.

Prefabricated skyscraper Sky City in China

Prefabricated skyscraper Sky City in China

A steel frame provides structure as the panels are installed in place and connections are made.  The speed comes from special tools and jigs that have been created to allow for quick and efficient installation.  Because each panel is installed in basically the same way each time, it allows further efficiencies in installation, saving valuable time.

Prefabricated skyscraper Sky City in China

Is It Green?

  • 8″ of insulation
  • quadruple-glazed windows
  • 3 stage air purification, cutting down particulates by 99.9%
  • 7 air changes per hour, with 100% fresh air run through heat recovery ventilators
  • combined heating, cooling, and power system that saves 80% on energy
  • saves 15,000 concrete trucks

The building is built for function, not form, so there aren’t a lot of architectural details.  The good news is that the design can be easily replicated, and the heart of the project is good, efficient, clean living space for employees and their families.  And talk about fast!

Source and Photos: Tree Hugger



Dawn Killough

has over 15 years experience in the construction industry and is the author of Green Building Design 101, an e-book available from Amazon. She is a LEED AP and Certified Green Building Advisor, and has worked on the LEED Certification of three projects in Salem, Oregon.