Changsha, China: It was snowing in Changsha on January 7, 2024, when flatbeds rolled onto an empty lot carrying steel boxes. Five days later, a 26-story apartment tower stood in their place.
The Jindu Holon Tower, built by BROAD Sustainable Building, has drawn international engineering acclaim as the largest demonstration yet of modular high-rise construction. But for the company, it marks the end of a 17-year journey that began in disaster.
A magnitude-8 earthquake in Sichuan in 2009 toppled reinforced concrete towers like sandcastles, killing tens of thousands. BROAD Group’s founder decided traditional building methods had to change. BROAD Sustainable Building was launched to pioneer modular construction that could bend, not break, in seismic events.
Conventional concrete mid-rises can take three years to build, with daily truck traffic, road closures, and weather delays. Major concrete repairs often follow within 5-7 years. In Hunan, the process looked different. Trucks delivered 12-meter-long stainless steel modules, each 3 meters high and 2.4 meters wide. Cranes stacked them while crews bolted them together. No concrete was poured. No welding was done on site.
Each module arrived from the factory with plumbing, windows, HVAC, lighting, and kitchen cabinets already installed. Factory production took 21 days. On-site assembly took five. Units were handed over fully fitted except for portable items like refrigerators and beds.
BROAD uses a patented stainless steel “sandwich” called B-CORE for its load-bearing structure. “We switched to stainless steel about five years ago,” said Andrew Zimman, marketing director at BROAD Group USA. “We realized stainless steel had great ductility. That’s why we chose it for our load-bearing elements. We’re the first to do so.” The design is meant to flex in earthquakes and resist corrosion.
The system has another advantage: buildings can be unbolted, unstacked, and trucked away. No demolition, dust, or landfill waste. “There’s no welding on-site. There are only bolts,” Zimman told the French Modular Building Institute, which gave BROAD its 2022 Innovation of the Year Award. “Select and position, stack, bolt, connect the utilities, and you’re good to go.”
The company says the steel modules have no set height limit. Projects are in the pipeline for Ohio, Texas, California, the Philippines, and the United Arab Emirates.
For cities weighing zoning changes or disaster risk, the message is simple: if the building has to go, it can literally go.
