Broad Sustainable Building (BSB), a Chinese construction company, has achieved an incredible feat by constructing Mini Sky City (also known as J57), an 800-apartment building comprising 57 stories, in just 19 working days!
The visionary behind this remarkable project is Zhang Yue, a Chinese entrepreneur often likened to Elon Musk for his drive to initiate revolutionary changes.
Located in Changsha, Hunan Province, in southern China, the glass and steel building was assembled at a remarkable pace of three floors per day using a modular method. Unsurprisingly, modular construction is among the top trends in the construction industry.
“With the traditional method, they have to build a skyscraper brick by brick, but with our method, we just need to assemble the blocks,” company engineer Chen Xiangqian said.
To achieve this goal, they worked on the construction of Mini Sky City in two phases, which were interrupted by bad winter weather. A captivating time-lapse video showcasing the rapid assembly of Mini Sky City has gained widespread popularity on Chinese video-sharing platforms since its initial upload on YouTube.
BSB spent around four and a half months fabricating the building’s 2,736 modules before commencing construction and utilizing 1200 workers to accomplish the remarkable feat.
While modular methods have been used for high-rise apartment blocks in other countries, there are some concerns among critics that it may lead to overly uniform architecture in cityscapes.
“It is not perfect, and it does not meet all kinds of personalized demands,” Liu Peng, the associate director of the engineering consulting firm Arup Beijing says, “People nowadays want more personalized architecture.”
Despite such concerns, Liu believes the method is promising and could become a safe and reliable approach to quickly building skyscrapers.
Although the height of Mini Sky City was originally planned to be 90 storeys, it was reduced due to its proximity to the airport. Nonetheless, standing at 200 meters tall, the building still stands out as you leave the city for the airport.
The skyscraper, with its remarkable features, including earthquake resistance, is set to offer space for sale.
A New Era Of Construction
As reported by the BBC, BSB founder Zhang’s ultimate goal is to spark a revolution in the construction industry. Mini Sky City’s astonishing construction pace of three floors per day is a testament to the company’s dedication to implementing groundbreaking and efficient building techniques. This achievement has garnered considerable attention and admiration, highlighting Zhang’s determination to redefine the possibilities in the field of construction.
BSB has even bigger plans in mind. They aim to construct the world’s tallest building, called Sky City, surpassing the height of the Burj Khalifa in Dubai. Standing at an impressive 220 stories high, Sky City is intended to be completed in just seven months, a fraction of the time it took to build the Burj Khalifa, which required five years to complete.
Sky City will be a comprehensive vertical living space, equipped with various amenities, such as an indoor farm and a helipad.
The modular design approach has been around for decades, although on a smaller scale, with Ikea being a notable example. Ikea’s modular furniture allows customers to customize and combine different pieces to suit their preferences, offering flexibility and adaptability over time.
Similarly, BSB’s skyscrapers follow a parallel principle. Steel is brought into their factories and assembled into modules, such as columns or cross beams. These modules are then transported to the construction site, where they are put together to form the complete building.
In line with their commitment to green construction, BSB uses ArcelorMittal Differdange steel, which is entirely made from scrap materials. Their sustainable efforts have earned them recognition as a pivotal player in promoting sustainable building practices, a growing need in the construction industry.
BSB’s choice of HISTAR steel, crafted by the HISTAR steel company in Luxembourg, demonstrates their dedication to utilizing high-quality materials. HISTAR steel, known for its exceptional weldability and ductility, has been widely adopted in the construction of numerous skyscrapers globally, including renowned landmarks like the Freedom Tower in New York and the World Financial Center in Shanghai.
By employing modular construction, BSB aims to revolutionize the construction industry and construct towering structures like Sky City in record time, shaping the future of high-rise building projects.
This is undoubtedly a brilliant initiative, welcoming in a new era in the construction industry. The current business landscape calls for organizations to revolutionize construction company finances and procedures to maintain relevance in the evolving times.
Sustainable Building
While some online debates about the building’s safety persist, its proponents highlight its sustainable and environmentally friendly features, underscoring the potential of innovative construction methods to reshape urban landscapes rapidly and efficiently.
He Youxian, an executive responsible for overseeing the Mini Sky City project, revealed to China Daily that the building is designed to withstand a massive 9-magnitude earthquake, showcasing its robust engineering and safety measures.
The construction process relied on factory-fabricated steel components and on-site assembly, utilizing flanges and high-strength bolts to connect the building elements. By incorporating preassembled floor slabs, lightweight wallboards, and other prefabricated materials, BSB demonstrated not only an expedited construction process but also a cost-effective and sustainable approach.
BSB architect Xian Min Zhang emphasizes the environmental benefits of their modular approach, as it significantly reduced concrete usage, avoiding the need for around 15,000 concrete trucks. This reduction leads to substantial cost savings and helps minimize airborne dust emissions, making it an environmentally friendly choice.

The achievement of Mini Sky City is not the first time for BSB to display its remarkable construction capabilities. Prior to this project, the same group constructed a 30-storey building in an astonishingly short span of just 15 days, further emphasizing their expertise and efficiency in the field of rapid construction.
BSB’s groundbreaking accomplishments have solidified their reputation as a leading force in innovative and speedy building techniques. The use of the innovative modular technique, resembling LEGO blocks, allowed them to complete an impressive three floors every day and earned them the prestigious CTBUH Innovation Award in 2013.
So, What Is Modular Construction?
Modular construction is a method of building where structures are fabricated offsite in a factory-controlled environment before being transported to the final location for assembly. This approach has been in use for many years but is increasingly gaining popularity across a wider range of construction projects, including offices, hospitality buildings, residential properties, and more.
The process involves manufacturing modular buildings in sections away from the construction site. These prefabricated modules are then delivered to the desired location and assembled to create the final building design. About 60-90% of the construction work is completed in the factory, either as complete structures or as modular subassemblies that are later combined for larger projects.
Modular construction has a long history, dating back to the 1830s when a London carpenter named John Manning built a prefabricated home for his son. This home was constructed in parts and then shipped from England to Australia, where it was assembled. The popularity of modular construction grew during the California Gold Rush in the 1840s, and it was used to build the ‘Crystal Palace’ for Britain’s Great Exhibition of 1851. The method gained further traction during World War II and the rapid post-war rebuilding of homes. The rise of modular construction in the USA led to the establishment of the Modular Building Institute.
The Benefits And Challenges Of Modular Construction
Modular construction offers several advantages over traditional construction techniques, such as reduced delays due to weather and onsite issues, higher product quality in factory-controlled conditions, and easier material supply control, leading to reduced wastage and environmental impact.
The modular approach also allows for the simultaneous construction of different parts of the building, making the process more time efficient. Additionally, modular construction is well-suited for remote locations, where onsite building could be challenging or costly.
One of the key advantages of offsite construction is the ability to use lean manufacturing techniques to create the modules efficiently. These modular units can be placed end-to-end or stacked up to create different configurations. Onsite assembly involves connecting the modules using inter-module connections or inter-connections to securely tie the units together.
However, some challenges associated with modular construction include the space required for transporting finished modular building sections and potential limitations on the size of each modular unit, which can impact room sizes.
The applications of modular construction have expanded beyond temporary structures and are now used for various purposes, including offices, homes, sports halls, and more. The modern wave of modular buildings demonstrates their versatility and ability to provide cost and time savings while maintaining comparable quality to traditional builds.
Volumetric Modular Construction
Modular buildings generally fall into two categories: permanent and temporary. Within these categories, the actual buildings can vary widely, ranging from “flat-pack” solutions to façade systems and those where a significant portion of the construction is completed offsite before being delivered and put together. An example of this is Volumetric Modular Construction.
Volumetric modular construction is a type of modular construction where, as much of the building as possible is completed offsite. This includes fabricating internal finishes in factory conditions and reducing the need for tradespeople on the construction site. This approach improves health and safety by reducing the number of people onsite and also accelerates the building process.
Permanent modular buildings, such as prefabricated homes, adhere to standards equal to or higher than traditional site-built properties, ensuring a high level of quality control. The construction process utilizes various building materials, such as concrete, steel, or wood, and is able to accommodate the incorporation of windows, power supplies, water and sewage pipes, telecommunications, air conditioning, and more.
Many of these additional features can be installed before the modules are taken to the construction site, saving time during the final assembly. Permanent modular construction (PMC) structures are designed to remain in one location after assembly and can include multiple stories as allowed by building regulations.
The design phase plays a critical role in modular building creation. Design for Manufacture and Assembly (DfMA) practices are used to ensure precise assembly tolerances, enabling adjustments for any slack or misalignment that may occur during assembly. CAD systems, additive manufacturing (3D printing), and manufacturing control systems are crucial in modular construction because the components cannot be easily realigned onsite.
Overall, modular construction is a versatile process that enables the creation of various building types and floor plans in a controlled environment, resulting in efficient, high-quality, and cost-effective structures.
The Varying Aspects of Modular Construction
The cost of modular buildings varies depending on the project’s scale and the types of materials used. Factors such as internal fittings and fixtures can also impact the cost. However, case studies demonstrate that modular construction can offer significant savings when compared to traditional construction methods due to reduced project delays and the ability to work on the structure offsite while the site is being prepared.
The lifespan of a modular building depends on whether it has been designed to be temporary or permanent. Permanent modular constructions (PMCs) are built to meet or exceed the same building standards as traditional builds and can last for decades with proper maintenance.
To Sum Up
The use of modular construction has proven to be a game-changer for the construction industry. This innovative approach allows for the offsite fabrication of building components, resulting in faster construction timelines, enhanced quality control, and significant cost savings. By utilizing modular units that can be easily assembled on-site, businesses can achieve greater efficiency, sustainability, and adaptability in their projects. As more companies embrace this method, we can expect to witness a shift towards more streamlined and sustainable construction practices, shaping the future of the industry for years to come.
The story of BSB is not unlike Being Humans – who similarly seek to revolutionize the ways of doing business by automating document processing. To learn more, book a free demo.