And there is a reason for that. It took just six days to build the Ark Hotel in Changsha, China. According to the video, no stationary cranes were used in construction and there wasn't single injury among the site's workers.
The 15-story sustainable hotel already had its foundation but using pre-fabricated columns and modules as well as modern construction techniques, construction workers took just 46 hours to finish the main structural components and another 90 hours to finish the building enclosure.
Level 9 Earthquake Resistance: diagonal bracing structure, light weight, steel construction, passed level 9 earthquake resistance testing
6x Less Material: even though the construction materials are much lighter(250kg/m2) than the traditional materials(over 1500kg/m2), the floors and walls are solid with surefootedness, airtight and sound-proofing
5x Energy Efficient: 150mm thermal insulation for walls and roofs, triple glazed plastic windows, external solar shading, heat insulation, fresh air heat recovery, LED lighting, yearly HAVC A/C energy consumption equivalent to 7 liters oil.
20x Purification: after 3 levels of purification, the purification efficiency for fresh air reaches 95%-99.9%; air exchanged 1-2.5 times per hour, and indoor air is 20x cleaner than out door air
1% Construction Waste: all components are factory made, construction waste, mainly package materials, result from on site set-up only and amount to 1% of the total weight of the building
If we believe the sources on the internet, this hotel construction caused only 1% material waste as compared to the building industry average of 10% for in-place steel and concrete construction. Clearly, this well planned, coordinated and executed project sets a perfect example for lean construction community and for the construction industry as a whole to understand the value of eliminating waste from the projects.