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World's Tallest Building Sky City-1 Changsha China and BIM, Lean and Green - What might be coming?

I feel fortunate to be living in an era when there are Computers, iPhones, iPads, Androids, Google Glasses, Google Earth, Facebook, Twitter and Broad Sustainable Construction. All but the last one out of my list are pretty obvious and I do not feel explaining why they are awesome.  However, I feel like talking a lot about Broad Sustainable Construction, a company which is based out of China and doing miracle after miracle and revolutionizing what world calls development. As a matter of fact, China is doing great with several other things too. But this blog won’t be talking about that.

At this very moment (January 5th 2013) Broad Sustainable Construction is building world’s tallest building – Sky City –1, which is almost a kilometer high (838 m/2749 ft to be precise) with 220 floors. They are set to complete the construction of this building within 90 days. This is remarkable and revolutionary. They claim to prefabricate 95% of building off site. Guess what, whole world is trying to bring lessons learned from manufacturing to construction (in the form of lean principles from more than 20 years now) and this project’s team is writing history by doing just opposite. They are using best of both worlds. They are building one of a kind product (this building) and they are using assembly lines to build 95% of it.

The three pillars of successful project - Time, Cost and Quality need to be evaluated for this project. At this moment, one thing is sure that Time being taken in this construction is the shortest in the history. Cost of construction and quality of construction can only be evaluated once the project is finished. But, I like to think they will build it for less per square feet cost than most of similar construction in the world and this building will serve the purpose as intended by its designers. 

Image Reference: Treehugger

Here is what Broad Sustainable Construction’s architect Xian Min Zhang has to say “China cannot pursue the American or European lifestyle, it cannot afford it: work somewhere and live somewhere else, using cars and roads to connect.” So they are building a city with everything in it. This building, which is also a city, will habitat 17,000 people, will have 5 schools, a hospital, a hotel for 1000 guests and 17 helipads.

The very existence of this audacious project changes a lot for construction folks. Industry needs to rethink the role of building information modeling (BIM), lean construction, sustainable green construction, embodied energy, information technology for construction, automation in construction, prefabrication, construction materials, construction methods and all the knowledge about construction that is based on Pre-Sky City – 1 era. If buildings will be built like this and time, cost, quality, safety and customer satisfaction are achieved successfully, application of this knowledgebase will change significantly.

I do not want this to be an informative post, but I do want readers to think how future would look like for them if this is the way we plan to build. We could very well be importing entire buildings in few years……………

So, I would put forward my guess about how BIM, Lean and Green are being applied in this building (again following section is just my guess and not any factual information)-

Building Information Modeling (BIM) at Sky City -1

My guess is that BIM is extensively used in Sky City -1 to make sure that everything goes where it is supposed to go on job site. Entire building’s model is built up to the nut and bolt level (Level of Detail -5 in BIM world). The data produced for this building must be humongous and unprecedented efforts would have been made by engineers and architects for coordination. What tools are they using for this coordination? I do not know. (Let me know what you think in the comment section below). The foundation is built in-situ and 95% of building is prefabricated. A lot of steel (some 207 thousand ton according to estimates) needs coordination, let alone mechanical, electrical and plumbing (MEP) coordination. Are they preassembling MEP in addition to prefabrication? Probably the answer to this question is Yes. So here is what’s happening. There are a lot of big pre assembled components that need coordination and BIM sure is being used for coordinating on Macro level too.

So they are using BIM for coordinating at micro level, using that for prefabricating and preassembling, and coordinating big pre assembled components using BIM again.
Use of information technology tools including internet, world wide web, analytical and intelligent IT tools got to be huge on a project of this magnitude. We ourselves are building one such tool and wonder how beneficial such tools could be for preassembly, prefabrication and just-in-time delivery.

Image Reference: designMena

Lean Construction at Sky City-1

The very core of this building’s construction method makes it Lean. The selection of this method itself eliminates a lot of waste and produces value for building occupants, and therefore makes the process lean. The 7 well know wastes must be significantly reduced. Here is what might happen with this building and waste produced due to its construction-
  •  Transport (moving products that are not actually required to perform the processing) – A lot of things associated with construction, including temporary structures and construction equipments, would not be needed anymore. The assembly lines used in manufacturing are already proven to be better than on site production in construction.
  •   Inventory (all components, work in process and finished product not being processed) – A lot of time and energy on construction sites goes into managing the inventory on job site. If done correctly, Sky City-1 would produce minimum inventory management requirements and waste due to inventory will be minimal
  • Motion (people or equipment moving or walking more than is required to perform the processing) – On job site logistics planning and arrangement for one building itself is a lot of waste, it requires significant movement of man, machine and material. Pre fabrication in a controlled environment using assembly line would certainly reduce this waste.
  •  Waiting (waiting for the next production step) – If 95% of building is pre assembled the waiting time will be as good as the manufacturing facility’s efficiency and lean practices on factory floors. This will be better than waiting time needed for construction with other construction methods.
  • Overproduction (production ahead of demand) – If done correctly, Broad Group won’t have to do a whole lot of extra production because building would need specific amount of component of a certain kind.
  • Over Processing (resulting from poor tool or product design creating activity) – This could be a problem if processes are not managed properly at factory floors.
  • Defects (the effort involved in inspecting for and fixing defects) – Again, factory floor lean practices along with the accuracy of assembled component coordination and installation would significantly reduce defects on this project.
About the produced value; it completely depends on user’s perception. If people using this building find that this building gives them what they expected, at the cost they expected, then value produced and waste reduced would make it one of the leanest project on the planet.

This will be an interesting question to think about - If used, how the use of Last Planner System, Set Based Design, Value Stream Mapping and Target Value Design will pan out on this project?

Sustainable and Green Construction at Sky City-1

One thing is sure about this project, if built in given time frame this tower will be relatively less disturbing for at least for the neighborhood it is built in. Construction material, site selection, use of energy, water etc would depend on its design and construction.

However, I believe this will be highly sustainable in construction phase as there will be less trucks and vehicles going back and forth to the job site, there will be less dust, smoke and other chemical particulates. All these would be done in a controlled condition that would produce higher degree of environment friendly results.

There are engineers who deny the possibility of building this tower in 90 days. WSP’s structure engineer Bart Leclercq says he would retire if Broad Group builds this tower in the time they claim they would. So the question is not whether to change the way buildings are built but rather the question to ponder is whether building built in this fashion will be viable and acceptable technically, financially, economically, environmentally and socially. Where are we going with this? Please feel free to share your thoughts in comments section.

Information Links are in References Section on this page.


  1. Very interesting article - but having just come back from China, and observed workers working on at least the 88th floor with no edge protection - it would seem that H & S should be the priority here

    1. I deny that construction has started at all, I cant find any pictures of the construction site and there is very little press on this subject. Not to mention I searched Chinese websites too. Can you help me?

    2. I think comment was about some other building. Author pointed out the safety concerns in such construction which is legitimate.

  2. Health and Safety sure need to be the first priority and that's where the customer satisfaction and value part comes in. It is on people's perceived value. So, value for Chinese people and facility's users makes this project a success or a failure.

    1. Cant find any pictures of the construction site or much News articals coming from China on the subject. You would think China would report on it more... Seems fishy.

  3. As the collapse of such mega building would kill ten thousands of occupants, I guess the Skycity should be formally banned by the authorities and is the end of planning application in early 2013 instead of what has been claimed that January 2013 should be the start for the construction.

  4. Here is what Chinese websites said in November 2012 about the same concerns over safety of occupants in this building - "Grounds for concern over world's 'next tallest building"

  5. Have used about half of these. My tool of choice these days is by far the best team support tool I've tried. And it is free.

    Angela West

  6. As the collapse of such mega building would kill ten thousands of occupants, I guess the Skycity should be formally banned by the authorities.

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  7. Updates -


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