From Investment Banker to Resilience Expert

Ken Calligar knows all about being buffeted by headwinds and putting out fires from his 30 years as a Wall Street investment banker. But these days, Calligar is known for his ability to develop residential and commercial buildings that stand up to fury and flooding from hurricanes, intense earthquakes, and even wind-whipped wildfires.

Unlike many people in the construction industry, Calligar, CEO of RSG 3-D, didn’t grow up with sawdust in his blood in a multigenerational family of builders.

“I got into the business of creating resilient buildings by accident,” Calligar says. “I was surrounded by sustainability businesses such as solar energy companies and alternative energy companies back in the early 2000s as a private equity investor helping small companies get to the IPO stage.”

“Clearly, building products is not an emerging industry, but the shifting demands of customers, regional resilience needs, and upgrading codes is creating a giant disruptive phase,” says Calligar. He believes that traditional products and methods that many companies are developing are not capable of responding to the new market needs.

An introduction to a client looking into panelized building – using prefabricated walls and parts manufactured in a factory – as an affordable housing solution in Africa sparked his interest in the future of building techniques. Calligar further nurtured this interest at trade shows and on tours of building sites in Africa, the Middle East, and Europe.

“I couldn’t find a better building technique than the RSG 3-D reinforced panel system, so eventually I bought the company,” he says. RSG 3-D builds modular panels of steel and concrete with polystyrene foam at their plant in Mexicali in Baja, California. Inside each panel is a welded wire truss system that repeats every eight inches. “The system creates a ‘perfect wall’ that also works as a floor, roof, or foundation slab,” Calligar says.

The system provides speedy construction of modular parts in a factory, which is 20% to 30% faster than building onsite. The factory-built process reduces waste because of the lack of exposure to the elements and because of automation, and results in an energy-efficient building that is 60% to 70% more efficient to heat and cool compared to a similarly sized building. The resulting buildings are resilient to natural disasters and extreme weather events.


Prefabricated modular construction has been around for decades, but the buildings are often limited in height because of the need to transport the wall panels to a building site. At the International Builders Show in Las Vegas in January 2023, RSG 3-D built a 22-foot-tall booth in the convention center to demonstrate the versatility of their system.

“It was good timing because we were swamped with inquiries from builders from the West Coast of Florida grappling with the aftermath of Hurricane Ian,” Calligar says. “We offer a building system, not just a product, that we think is the future because it’s the most resilient system I can find.”

While the technology is new to many builders and developers and Calligar has led the company just since 2018, the building system has been used for more than 10,000 construction projects in 20 countries for three decades without a single incident of damage from a storm, an earthquake, or a wildfire. Uses include everything from luxury resorts to tiny homes, homeless shelters, prisons, and military installations that have received NATO-approved ballistic ratings.


The frequency and intensity of wildfires and other extreme events such as hurricanes, tornados, floods, and earthquakes are anticipated to increase because of climate change, according to the Climate Change 2022 report from the Intergovernmental Panel on Climate Change. Extreme storms and natural disasters have already caused billions of dollars in lost property, a problem that has accelerated demand for RSG 3-D.

Buildings constructed with the RSG 3-D system can withstand wind speeds up to 300 miles per hour and have the structural strength to hold up to an earthquake at 11.0 on the Richter scale, even though there’s never been a recorded earthquake of that magnitude, according to researchers at the University of California at Irvine.

The panelized system garnered attention in 1992 when 14 homes built with the system by former President Jimmy Carter and Habitat for Humanity were the only ones left standing in the Liberty City area of Miami after the devastation of Hurricane Andrew hit.

“At that time the company had no ability to sell the system and they were overrun with demand,” Calligar says. “They eventually merged with a company in Mexico to continue building the panelized system for a limited number of clients.”


While the prime benefit of the RSG 3-D technique is resilience to natural disasters and weather events, the building system is also extremely energy efficient because of the consistency of the insulation in the walls. The concrete used with this building system prevents rot, mold, and leaking, and makes the home resistant to insects and vermin. The buildings typically require less maintenance over time because of the precise construction technique and the durability of the materials used. The result: less money spent over time on energy costs and maintenance.

“We also reduce carbon emissions because our systems used 40% less concrete compared to a cast-in-place building,” Calligar says. “This is not only good for the environment, but this provides benefits to commercial builders and developers who want to lower their carbon emissions.”

Calligar’s goal is to provide the building system to future-proof entire communities, particularly in hurricane-prone areas in Florida and the Gulf Coast and in wildfire-prone areas in the West. He notes that while many communities are built with modular components that provide energy efficiency and improved engineering, they still lack resiliency if they are built with a wood core.

“Those homes don’t have the performance level of a house built with steel and concrete during a seismic event, a wildfire or a flood,” Calligar says.


As the company ramped up business, Calligar operated an extremely lean business to control costs. Now, he is focusing on hiring senior-level staff, expanding the product line, marketing, and strategic partnerships.

“Andersen Windows committed to RSG 3-D early and we’re very appreciative,” Calligar says. “StrucSure and Lloyds of London are providing best-in-industry structural warranties to RSG 3-D builders, and additional alignments like these will be expanded.”

The company’s plant in Mexicali provides enough panels for 4,000 houses per year. They plan to build another manufacturing plant in the Southeast U.S. to be closer to Florida, the Caribbean, and the Gulf Coast, where needs are high for buildings resilient to hurricanes.

Calligar says the biggest challenge his company faces is long-term scalability. In the short term, RSG 3-D has so far managed the acceleration of demand that stems from natural disasters and interest among builders for larger and more complex projects using their system.

“We have runway as a business because of the longer-term sea change that will demand better building performance in the coming decades,” Calligar says. “Client education is the key to adoption and scaling of our company.”