Why Isn't the World Made of Lego Blocks?

Lego bricks are among the most durable building materials in existence. So why don't we make everything out of them?

- By Tatyana Woodall and Jennifer Leman

In the summer of 2009, more than 4,000 volunteers flocked to dorking, england, to help former Top Gear cohost James May realize his childhood dream of building a real house out of Lego bricks. Over roughly one month, more than 3.5 million plastic blocks were transformed into a two-story home complete with Lego furnishings.

Guinness World Records dubbed May's structure the largest "life-sized house made from interlocking bricks." May's house wasn't alone as a life-sized Lego build. In 2016, Land Rover built a 5.8-million-brick model of London's Tower Bridge sturdy enough to drive its SUVs across. And in 2018, an Australian team built a full-size Lego camping trailer. Such accomplishments beg the question: If we can build a Lego house or bridge or camper, why isn't more of our world made of Lego blocks?

Lego bricks are made out of a hard plastic called acrylonitrile butadiene styrene (ABS) with a manufacturing tolerance of roughly 0.01 mm. "Lego bricks are very precisely made," says Barnaby Gunning, the London-based architect who designed May's house. This precision makes them a reliable and efficient construction material.

The ABS is semi-pliable, allowing bricks to fit together using a friction-dependent connection called a snap fit. The friction between the top stud of one brick and the interior tubes of the brick atop it hold the pieces together, but not so much that they're impossible to pull apart.