
Why aren't large Lego bricks used to build full-size buildings?
We've all dreamed of building a Lego castle, but it'll probably be cost rather than structural integrity that brings this grand design to a halt.
Asked by: Edward Seymour, Hove
The plastic used in Lego – a type of polymer called ‘acrylonitrile butadiene styrene’ (ABS) – is surprisingly strong. In fact, it’s able to withstand compression better than concrete. Researchers at the Open University in 2012 found that an ordinary-sized Lego brick can support the weight of 375,000 other bricks before it fails. Theoretically, that would allow you to build a tower almost 3.5km high! But Lego is far too expensive to be used as a large-scale building material.
There are, however, Lego-style construction techniques that use other materials. ‘Insulated concrete formwork’ (ICF) uses hollow polystyrene blocks that are assembled into walls and then pumped full of concrete. The polystyrene acts as a mould and provides insulation. And in developing countries, interlocking blocks of compressed earth mixed with a small amount of cement are used as a cheap alternative to bricks and mortar.
Read more:
Authors

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.
Sponsored Deals

May Half Price Sale
- Save up to 52% when you subscribe to BBC Science Focus Magazine.
- Risk - free offer! Cancel at any time when you subscribe via Direct Debit.
- FREE UK delivery.
- Stay up to date with the latest developments in the worlds of science and technology.