What is used to build a 30-story building in 15 days?

Are you asking about Hunan New Ark Hotel?

All of its construction materials are prefabricated and components are manufactured to specification off-site, so there is very little waste. It took construction workers only 46 hours to complete the main structure of the New Ark Hotel, and the sealing took only 90 hours. The entire building is soundproofed and thermally insulated, and given the air pollution China faces, every room has an air quality monitoring system. Although they don't work all night, construction workers still work long hours and usually don't finish work until 10pm and go back to rest. Their previous record was to build a 15-story building in 6 days. In comparison, the New Ark Hotel is even more eye-catching.