We have been closely tracking China’s Broad Group and their prefabricated factory mass produced ‘Can be Built’ skyscraper technology. Six months ago they had earthquake certified a scale model of their 30 story building. now they have built an actual 30 story building in 15 days at the end of 2011.
UPDATE – There is a follow up article that discusses the impact of this technology on skylines of cities in the future. A big factor will be the lowering of costs by three times to ten times. It will become affordable to build three times higher for the same price.
This is one of the key technologies to watch for the next decade or two. The reason is the construction methods use far less cement and are more energy efficient. They will also enable faster urbanization of the developing world (not just China.) With state backing Broad Group will have this technology in use for more high rise commercial construction by 2020. This is part of the mundane singularity of technologies that mostly exist now and can high impact on the world.
The buildings are five times more energy efficient in operation and use about 6 times less cement.
They plan to build one hundred and fifty 30-story apartment building, hotel, office plans using the new system. They have started building a 1.33-million-square meter “NO.1 Sustainable Building Factory” and it will be able to produce 10 million square meters of mass produced skyscrapers (about 100 million square feet) each year. The 30 story building is 183000 square feet so the factory can produce about 500 of the 30 story building each year and many more factories will be built.
The Changsha Broad Air Conditioning Company has unveiled designs for the 200-storey Sky City tower, a sustainable mixed use project. At 666 meters tall, the building will house 1.2 million square meters (12 million square feet) of space for residential apartments, retail, offices, restaurants, schools and a myriad of other facilities. The building will be manufactured in a factory and assembled on the construction site. Additionally, the tower will have the capacity for 70,000 to 110,000 residents. It will use 400 kilograms (1000 pounds of material) per square meter). 480,000 tons of building. Even with reducing the occupancy by half so that units are 1320 square feet instead of 660 square feet the amount of material is 12 tons per person for 40,000 people. The Broad Group building also includes offices and retail shopping. Instead of being 6 times more efficient with material it is more like 8-10 times, since it is replacing 72 tons of house and the extra buildings for offices and shops. It is 20 times more efficient if the higher occupancy levels are used.
Other Broad Group Technology
Non-electric air conditioning withstood the world’s toughest stress test serving over 250 pavilions in the largest, crowdest, hottest, and most dynamic architectural site. Achieving “zero fault” operation for 6 months, contributing to a successful Expo. Also saved 73,000 tons of CO2 emissions, and realized “Low Carbon Expo”.
Successfully developed super-size “ Heat Recovery Fresh Air Unit”, realizing 99.9% air purification efficiency, ensuring abundant fresh air supply and high efficiency heat recovery.
Plans for a 666 meter tall skyscraper
A Chinese company developed new factory prebuilt construction that can make a 15 story building in 6 days plans to build the second tallest building in the world over 6 months. 93% of the construction work is done in the factory vs at most 40% in western countries.
The Changsha Broad Air Conditioning Company has unveiled designs for the 200-storey Sky City tower, a sustainable mixed use project. At 666 meters tall, the building will house 1.2 million square meters of space for residential apartments, retail, offices, restaurants, schools and a myriad of other facilities. The building will be manufactured in a factory and assembled on the construction site. Additionally, the tower will have the capacity for 70,000 to 110,000 residents.
They are trimming their costs to 7,000 yuan to 8,000 yuan per square meter. The company then adds its profit margin and sells its properties for around 10,000 yuan per sq m – or about half the price of properties in Shanghai outside the city center. This would convert to a 660 square foot unit costing about US$100,000. The whole building is 1.2 million square meters so this project will cost about US$1.25 to 1.46 billion and will sell for $1.83 billion. Numbeo has Shanghai cost of living and Shanghai apartment prices are currently three to six times as high to buy as these apartments would be
Comfort of Skycity
• 100% fresh air, no mixed with return air, eliminate infection. 3-stage filtered fresh air , 99% nano-particulates be filtered. Indoor air is 20-100 times cleaner than outdoor air. Central vacuuming system keeps indoor air quality.
• Space blocks and all rooms remain at 20~27 ℃ all year round, glass wall enable
sunshine lighting up the streets.
• The clear height of residences and office is 2.8m, the clear height of space blocks are 5.6m, 9m, 12m respectively.
• Four 4meter wide streets start from the ground to the floor 121 at 400m, the total length of street is 12km, shops, agriculture markets, handcraft shops, restaurants, amusement parks, sports centers, natatorium, cinemas, opera houses, museums, libraries, training centers, schools, kindergartens, clinics, banks, police stations, etc. on both sides of street, same as city downtown. Botanical garden, natural parks, fishponds, waterfalls, sand beach can be found in some floors, same as the suburban.
• 16 large observation elevators and 31 high-speed elevators can serve 30,000 people every hour.
• Level 9 earthquake resistance, scale model will be tested by national authorized institution.
• BROAD unique technologies “diagonal bracing, light weight, factory-made” ensure the
highest earthquake resistance level with minimum materials.
• Trapezoidal construction structure corresponds the law of mechanics, which can withstand earthquake and storm.
• Sky gardens locate on floor 71, 121, 156, 176 and 191(12,000m2 in total), also function as the helipads, which are able to evacuate tens of thousand people during fire emergency, provide extra fire protection than conventional skyscrapers.
• 150mm exterior insulated walls, triple-paned windows, exterior solar shading, interior window insulation and heat recovery fresh air, 80% more energy efficient than conventional buildings.
• Adopting “distributed energy system”, turbines provide power independently, exhaust from turbines is the source for cooling, heating and sanitary hot water. 50% more energy efficient than the power grid.
• Indoor HVAC is controlled by occupancy sensor, fan speed will be automatically adjusted to the lowest load when people left.
• Elevator generates electricity when ascending unload and descending full load, also choose the floor outside the elevator, and other electricity saving methods can save 75% more electricity than conventional elevator.
• LED lamp, 90% more energy efficient than incandescent lamp and 50% more energy efficient than fluorescent lamp.
• Separated drainage system, rain water is used for plant irrigation, bathing water will be directly drained after settled, bathroom sewage and kitchen waste go to biogas tank, biogas is used as fuel for air conditioning, and solid wastes become organic fertilizers.
• Annual energy conservation 60,000 ton oil equivalent
• Saving 600,000 ton construction materials
• Saving 1.4 sq. kilometers land (volume ratio 50)
• On-site construction waste is less than 1% of the total weight
• Zero raise dust on-site
• Zero water consumption on-site
• Recycle processes of living garbage from the building
• All steel structure, reuse after abandoned