10th Jun, 2015

How Shanghai engineers are building high-quality houses from container-like modules, and turning the traditional construction process on its head.

Article originally published in Home & Office Design, Summer 2015

Earlier this May, while most of Shanghai enjoyed a leisurely weekend, there was a flurry of activity over at the German Center in Pudong. One of the complex's buildings had recently met with the bulldozer, and cranes were hard at work assembling its replacement. But while an ubiquitous sighting in Shanghai, this particular construction zone differed in one key, critical aspect. Whereas many new buildings take months or years to complete, this one-a two-story office made of container like modules-was installed in just three days.

"The key selling point behind this type of construction was the speed of execution," says Oliver Tittmann, co-director of XCUBE, the Shanghai-based firm behind the new build. The German Center commissioned XCUBE, which Tittmann runs with co-founder Matthias Laufer, about a year ago with hopes of replacing the aging building with limited disruption. "They wanted to minimize the time between which the tenants had to move out, the existing building was destroyed, the new building placed, and the tenants moved back in," Tittmann recalls. Such a feat would have been impossible if XCUBE didn't specialize in modular-or prefabricated-construction, which involves moving the bulk of the building indoors onto an assembly line-in this case, a 2,000-square-meter warehouse in Taicang.

"Think of each module as a building block for a permanent building," Tittmann explains, speaking of the 20 foot or six meter-long steel module—similar in size and shape to your standard ocean-going container—that the firm uses as the base for their innovative buildings.All of the engineering—from the structure itself down to the wall panels, windows, electrical, ventilation and plumbing—is designed in-house; once the client signs off, those components are manufactured by subcontractors and delivered to the workshop. “Then we go in there with our team—and the materials we’ve gathered from various suppliers—and assemble a finished house,” Tittmann says, describing how technicians test-assemble each building indoors to install the facade, windows, roofing and connections, then transport the pre-fitted modules to their final destination via truck or a barge, allowing for a swift Lego-like assembly onsite.

Of course, modular construction depends on finding the proper module. "Repurposed containers are absolutely fantastic in concept," Tittmann explains. "The idea that you can take asteel box that lived five or 10 years on the ocean and has come to the end of its practical life as a shipping container, and that you can transform that into something that's comfortable and nice to live in, it's an architect's dream."

The reality, he says, is very much different. Most containers are pretty banged up afterfive to 10 years on the ocean (the standard life span of such a unit) and stripping the paint to remove all the dings is a massive effort in itself. They’ve also transported all sorts of goods during their decade at sea, including chemicals of unknown toxicity. "You have a wooden floor that's possibly absorbed lots of things," Tittmann explains. "Secondly,that wooden floor was treated with all sorts of chemicals at the origin so it wouldn't rot."China’s efficiency on recycling also complicates matters. "What they could sell to us or anyone wanting to do a build-ing, they could get just as much as scrap metal," he says, explaining how most “end of life” containers in China are cut down to scrap metal or used as extremely basic housing for workers.

Given the impracticality of finding a used container suitable for safe and modern living, XCUBE simply engineers its own. Each module (or "box,” in modular engineering parlance) is outfitted with non-toxic flooring, which isn't ideal for an ocean-bound box but works well for houses. Engineers are also free to experiment with the scale and dimensions, as they did in the case of the German Center. "We were fortunate that we could transport by truck, and we could send three-meter-wide modules," Tittmann recalls, describing units slightly wider and taller than a standard shipping unit. Because all of the design, engineering and the bulk of the construction had been done in-house, onsite assembly was limited to simply stacking the containers using a crane and a spreader bar.

"If you're working in a warehouse, which is a controlled environment, you don't have to face any weather issues like rain or heat," explains Laufer, whose background as a carpenter and engineer means that he manages much of the construction while Tittmann handles the business / buying side of things. "So if you put everything into a warehouse, you can structure a work sequence and control the whole working atmosphere," Laufer explains. "Long-term, I think this is probably—compared to traditional construction — much more efficient.”

Still, modular construction offers its own set of limitations—namely, that the engineersusually work within the confines of a standard shipping container, which helps keep costs low when sending the modules abroad on a long ocean voyage. If the dimensions vary by even an inch, transportation will incur extra charges. "You put it on a truck, it fits on the truck. It gets to the port, the crane picks it up like any other container," Tittmann explains. "If you change even one dimension on that box—the height, the width, the depth, the length, or you don't put the corner castings in the right place—it becomes bulk freight. Oryou need to negotiate with the shipping companies."

Modular housing has been around for a while, but the idea is still catching on in China.For now, much of XCUBE's work is exported abroad, either as pre-fitted modules or flat-packhousing (or kit), which involves engineering and shipping all of the components required tobuild a house or hotel, though they aren’t assembled in China. "A client will come to us ifthey need to build somewhere in the world where it's hard to find materials or labor, but where they want to build high-quality housing quickly," Tittmann explains. Recent projects have included a 131-unit student dormitory in France, as well as projects in Holland, the US, the Philippines and Mozambique. All are designed to last 50 to 70 years—the lifespan of a normal house—and adhere to the client's national building and safety codes.

"We want to make modular beautiful,” says Tittmann, describing XCUBE's delivery of premium, high quality products and precise engineering as the company’s competitive advantage. “We want to make modular housing sexy and permanent, and move away from the image that modular is a cheap, construction site solution or repurposed containers that only have five to 10-year lifespan,” he says. "You're moving construction from a construction site into a factory where we can replicate things, where we minimize waste, where we have good quality control. You don't buy a car from an artisan who builds each car one by one, you buy it from a factory. Our vision is that pre-fab and modular housing doesn't need to be ugly and low-end. It can be designer and yet very high-quality, because it’s built in a factory and we have strict quality control systems and procedures."