The Olympic Games are notorious for leaving burdensome buildings in their wake. Much of the swooping Olympic Park in Athens lies rusting and underutilized. Beijing National Stadium—or the Bird's Nest, that iconic architectural marvel of the 2008 Games—draws tourists, occasional soccer matches, and little else.

Nearly every city that's hosted an olympiad lives with a white elephant. This never reflects well on the Games, and the International Olympic Committee has in recent years directed organizers and host cities to be cognizant of "legacy mode"—what happens after crowds disperse, athletes leave, and the torch extinguishes. London offered a glimpse of this approach with the 2012 Games, which featured several easily dismantled stadia. Rio goes further still with structures that can be removed, rebuilt, and repurposed. Mayor Eduardo Paes calls it "nomadic architecture."

Future Arena, the handball venue, will provide the material to build four 500-student primary schools in the city's Jacarepaguá neighborhood. Workers will disassemble Olympics Aquatics Stadium and use the components to erect two community swimming centers; one in Madureira Park and one in the Campo Grande area. The International Broadcast Centre will become a high school dormitory. And Barra Olympic Park—a 300-acre, triangular peninsula that features nine Olympic venues—will host public parks and private development after the Games.

Aecom’s kit-of-parts concept for the Nomadic Stadia. AECOM

“It’s based around not leaving white elephants,” said Bill Hanway of AECOM, which created the master plan for the olympic parks in London and Rio. “We're at a stage in the Olympics where social and financial responsibility are much more important than they used to be.”

Such an approach is vital, he says, because most venues that host sporting events after the Games often have twice the capacity they need. Some of them aren't needed at all, and sit vacant.

The trick, Hanway says, is using prefabricated, modular parts—a decades-old technique enjoying renewed interest because it is cheaper, faster, and more sustainable than conventional methods. Advances in materials and techniques have made modular structures lighter, stronger, and more weathertight than before. Rio's nomadic venues feature puzzle-like compositions of shared components—standardized steel columns and beams, modular steel panels, concrete slabs, and event-specific elements like seating bowls, playing surfaces, and water tubs. After the Games end on August 21, crews will disassemble these structures, haul them to new locations, and reconfigure them.

The $38 million Olympics Aquatics Stadium, which features natural cooling and seating for 20,000 people, will be broken down to create two smaller pools beyond Olympic park. The challenge is disassembling and reassembling the enormous fiberglass tubs. Future Arena will come down much like it went up, and key components used to build four schools. Its lacy facade will become sunshades and rain screens, and its concrete ramps will provide wheelchair access.

Inside the Aquatic Stadium, which will become two smaller community pools. Its ducts are made of fabric, making them easier to construct and remove. Robb Williamson

The broadcast center's steel frame will provide the framework for the dormitory at a high school for gifted athletes at the Barra Olympic Park. The 18,250 seats filling the Olympic Tennis Centre will be reused elsewhere, as will much of the main souvenir shop.

That's the plan, anyway. Brazil's deep financial problems and turbulent political atmosphere could slow or scuttle that part of the plan entirely. Still, the idea shows how Olympic infrastructure can be reused.

"I think it's nothing short of a brilliant way to address building such massive infrastructure," says Irwin A. Kishner,a partner at Herrick, the New York law firm that worked on Yankee Stadium, the Meadowlands, and Red Bull Arena. "It adds another option to what can be a very wasteful enterprise."

Of the 30-odd venues at the Games, only Future Arena and the aquatic center are truly nomadic. Beyond those, the tennis and beach volleyball venues will be dismantled. London made greater use of temporary facilities, but much of the sporting infrastructure in Rio—including Olympic Stadium—existed before the olympiad, erected for events like the Pan Am Games and the World Cup.

You could argue that reusing existing venues is the most sustainable approach, especially in a city like Los Angeles—which is highlighting that approach in its bid for the 2024 Games. But Hanway says prefabricated structures that are quickly and easily assembled are perfect for cities that lack the infrastructure needed to host an olympiad. Jeff Keas, a principal at Populous, which designed the London Stadium for the 2012 Games, says temporary buildings can have a carbon footprint half the size of a conventional structure, and can cost 50 to 80 percent less. Building times vary widely, but most temporary buildings go up faster, too. Not having to maintain permanent stadiumscan save millions more.

“We need to build faster, lighter, and more sustainable buildings to face the environmental and socio economic challenges the world faces,” adds Hanway. This is true of all buildings, not just Olympic venues.