BROADCAST AND DIGITAL RESTRICTIONS** Broadcasters: None Digital: None **~ These are not your usual bricks.
In fact, they're made of urine - or, as these researchers call it, 'liquid gold'.
These scientists in South Africa create them with human waste, sand and bacteria.
Luckily, the final product is odorless - and it's hoped the world's first 'bio-brick' could improve sustainability in the building industry.
(SOUNDBITE) (English) SENIOR UCT LECTURER, DR DYLLON RANDALL SAYING: "If we consider for example the amount of waste water we produce from our homes, in terms of volume, urine only makes up one percent of that waste stream.
But it contains over 80 percent of the nitrogen, about 70 percent potassium and 50 percent of the phosphorus.
Now those are three key nutrients needed to make any organic fertilizer and literally we pee those away every single day and we flush it through our sewer networks.
Why shouldn't, why should we not be recovering it instead and basically making multiple products and in my mind, that's the way we achieve a truly sustainable future." The concept of using urine to grow bricks has previosuly been tested in the United States, using synthetic solutions.
But this is the first brick that has ever used real human urine.
They're created through a process similar to how coral reefs are formed.
Loose sand is mixed with bacteria, which breaks down the urea in urine while producing calcium carbonate through a complex chemical reaction.
The bricks are formed at room temperature, cutting out huge amounts of harmful carbon dioxide produced when making regular bricks that are kiln-fired at temperatures of 1,400 degrees Celsius.
But there is one obstacle preventing mass production: researchers will have to collect vast quantities of urine.
One brick needs about 20 litres of urine - but the researchers are hoping these bricks will be viable in the next few decades.