- Materials & Industrial Technology
How to Accelerate Building Speed?
Why Building Faster?
What drives people to chase building speed records? And what drives the Chinese to build so fast, like the 30-story hotel in Changsha that went up in just 2 weeks?
There can be many reasons to chase speed records.
- to safe time and money
- to meet client wishes
- to cut failure cost
- to obtain prestige and fame
- to develop a construction niche
In any case it is clear that the Chinese company BSB established its name around the world. The publicity is enormous around the plans to erect the tallest tower in the world in just 90 days, called Sky City One.
Chasing for Speed Records
The traditional speed to erect high-rise buildings is approximately 1 story per week. A 30 story building takes traditionally about 8 months to construct. The preliminary design process usually takes about the same time. In almost all cases there's time and information lost in the phase transitions. In this typical example the traditional process takes altogether between 1.5 to 2 years.
The 30-story hotel tower built in Xiangyin near Changsha, is erected in just 15 days (360 hours). This amazing improvement in speed cannot be achieved without rigorous changing the way construction projects are usually organized.
The preparation of the project and the whole way the project is organized from design, manufacturing and construction on site is totally reorganized.
Design & Construct
To increase building speed in any situation, the design and construction process has to be in the hands of one contract partner.
One contractor is responsible for design and construction, called design & construct contract.
In the case of the current record holder, the 30-story hotel, the design, production, and assembly is controlled by one and the same contractor.
The ultimate key matter is - cutting every loose dangling chain partner in the process chain and integrate it in the chain i.e. in the line of command and control.
Design and construct projects are cheaper and quicker finished. Safety is much easier to control, because the safety measures are partly integrated in the design.
Traditional projects have a much higher safety risk. A contractor can take construction details that can be so complicated to build, that they have large impact on safety during construction. These "impossible" details always slow the project down, and increase in most cases the safety risks dramatically.
Safety = Time = Money.
How High are the Safety Risks?
The quicker and the more efficient buildings are constructed, the less accumulated risk there is for safety if the risks themselves (as a result of the higher speed) haven't increased.
The safety on construction sites have been enormously improved in the last hundred years, mainly because accidents became more 'expensive', when a more humane approach was introduced on the workplace.
The fatality rate in the construction industry during the period the Empire State Building was built was 0.85 per million hours worked. The claimed 6 fatalities on the 7,000,000 worked hours is average compared to the average figures in the construction industry in 1930.
The construction speed of the Empire State Building was twice as fast as usual. Apparently was safety not negatively influenced by the higher construction speed.
What would you prefer? Exposing yourself 300 days in an environment with a fatal accident of 0.01%, or exposing yourself on 15 days in an environment with the same risk?
One things is sure. High building speeds do not increase the safety risks, it is even opposite.
Construction versus Mining
Safety risks in the construction industry are still very high compared with other industries. Construction is after mining the most dangerous industry to work in, while most people don't know this.
Mining is known as the most dangerous environment to work in. No doubt, everyone knows this. Every incident in mining is enlarged on TV worldwide, because it is catastrophic and worth broadcasting when a group of miners is captured in a dark cave deep down in the earth. It has a kind of horror entertainment.
In construction, the combination of:
- the use of machinery
- freedom of movement
- concentration on the job
can easily be a very toxic combination.
Accidents in the construction industry don't have the spectacular impact as in mining, but they occur as little events very often and this makes them so hard to control.
In the graph below you see how mining became much safer and approaches construction industry. The prediction is that around 2015 mining and construction are at the same safety level. Around 2020 will construction become the most dangerous large industry to work in.
Safety in Several Industries
How Attitude has Changed
There is hardly a safety culture in China, somewhat comparable with the mentality during the construction of the Empire State Building. The big difference between then and now is the state of technology.
There are no reliable public records of accidents on construction sites in China. It is absolutely unproven and subjective that this enormous speed has larger risks than "slow" erected towers in China.
The safety risks in the high speed construction projects are possibly even much lower, because the constructor is well organized, cannot risk bad publicity, and accidents therefore will have a negative impact on the building speed due to investigations. High speed constructing is also less difficult because of the standard components - this is a major risk cutter. So, high speed projects contains all ingredients to cut fatality risks rigorously.
90 to 95% of the components are prepared behind a computer and in the environment of the factories. Construction sites are dirty, exposed to the climate, use enormous amounts of energy, bad for the environment, and very hard to control on safety.
Perhaps it is not so bad to chase these records. Eventually are the environment and safety benefiting from this goal.
The Giant is Awake
Chasing for speed records in constructions is a new phenomenon. During the 20th century nobody was really busy with this. Smashing speed records requires a total other approach in constructing. The Chinese company Broad Sustainable Building made a hype from this. Suddenly questions start to rise around the world; why is our project running so slow? This question is answered further on.
The Empire State building still owns the record of the fastest built traditional building. To built this 102-stories traditional giant in less than 60 weeks was a smashing record. During the construction of the Empire State Building six workers died by falling down and an unknown amount of workers was severely injured.
China proved to be capable delivering high quality at an amazing speed, without uncontrollable safety risks. The giant is awake, not only in cheap production of electronics and cars, but also in improving construction techniques of giant buildings. That's another dimension!
Why do Traditional Projects Run so Slowly?
Traditionally, between 70 to 80% of the building parts are tailor made. This takes much more time to prepair and to make, it also gives higher risks on failures.
Average projects needs between 1 and 2 years to finish. The first part of construction projects look always very promising, when the concrete or steel structure is rising. After closing the building with roof, facade, windows and doors the projects progression is on 50%. For most of us it looks pretty finished, while the most difficult part is beginning, the battle for every square meter.
The second part of every project takes at least 5 disciplines; construction workers, electricians, mechanicals, plumbers and finishers of floors, walls and ceiling. They all need to be on the same place at the same time, while this is impossible. The main contractor who organizes the project puts the disciplines in a chain behind each other. Every discipline has also its limitations in speed and workers per area.
The always returning failure cost in traditional construction techniques are still very high, swinging between 5-10% of the total construction cost. Practically it means that between 5-10% of all work must be redone, needing the same disciplines again on the same place and disturbing the other disciplines. Repairing failure costs take including determination, analysis and repair between 15 to 20% of the construction time - a large amount.
This chain of working is absolutely redundant, but to innovate this needs time, effort and money. Construction projects are madly complex, while they appear to be simple, because we are used to buildings and their functions. Little changes in every complex process can have a high impact.
Most projects run on a fixed speed of $xx/m2/week (I don't publish these figures).
How to Increase Speed?
- the most simple way to increase construction speed is a Design & Construct project. It is cheaper and quicker, but difficult to start. It needs to be strictly organized with specifications and contract documents. You win 15% in time and save up to 5% in money.
- the more difficult way is how the Chinese organize their speed projects, is to move 90% of the construction to the design table and the factory. There is 0% space for errors on site once a project is started. In the factory the construction modules can be assembled parallel. Like in the car industry, a building is cut into little components and elements and assembled to ready modules easy to install on site. All connections like constructive, electrical, plumbing and mechanical are prepared in the factory. The failure costs are between 1-2% (in factory). It is more expensive to build because of the larger amount of high qualified personnel required for the work. The costs are comparable with traditional projects (if to plus and minus the differences), the quality is much higher. Buildings are more simple shaped, because of the standardized elements.
The Chinese are just running warm with their latest high speed constructions. It is a matter of years before the Chinese control all aspects of the factory construction processes totally, including safety and more freedom in architecture.
What the Chinese are doing is moving the construction process to the factory, which makes it possible to build everywhere in the world.
Within 20 to 25 years from now, the Chinese builders overrun globally the construction industry with their highly evolved construction techniques. The conventional construction processes with the high failure costs and high safety risks will have become an odd practice.
© 2015 by Buildreps