• Netanya Abramson

The Urine Bio-Brick: The Many Problems That Can Be Solved with Urine


Photo by Candice Lowin


The building industry is one of the biggest contributors to CO2 emissions, with the building and construction section contributing to 11% annually. The standard brick requires 2 kWh of energy and produces 0.41 kg of CO2. This might not seem like a lot, but over time using thousands of bricks to create just one house adds up. This releases a ton of CO2 which contributes to climate change and furthering extreme natural disasters; a sad reality when there are alternative solutions.

The bio-brick is one such solution to this problem, where urine is utilized to create a new building material akin to bricks. In this process, urine is combined with enzymes at room temperatures to create a solid mass with strength comparable to that of a limestone brick. It takes nearly no energy to create and produces very minimal carbon emissions. In addition, the excess urine can be used to create fertilizer and even potable water.

This solves other problems such as excessive water usage. Every time we go to the bathroom, we use clean water (more accessible to the majority of us than it is to many others all over the world) and flush it away with our sewage. Dr. Dyllon Randall, Associate Professor of Water Quality Engineering at University of Cape Town and project leader of the bio-brick project, lecture likens this to flushing away liquid gold in his 2018 lecture, since urine contains nitrogen, potassium and phosphorous: key elements required to manufacture inorganic fertilizers. Another problem is that natural phosphate rock is depleting at a rapid rate and it’s becoming increasingly difficult to mine this valuable resource.

Due to this, Dr. Randall emphasizes the need for us to rethink waste management and switch from a linear economy to a circular economy, specifically in the sanitation sector. There is a great need for a paradigm shift, linguistically and culturally, to look at urine as a resource instead of something we simply flush away. Utilizing urine to create new building materials would directly help to solve the UN’s sustainable goals 6 (clean water and sanitation), 9 (industry, innovation, and infrastructure), 11 (sustainable cities and communities), 12 (responsible consumption and production), and many more indirectly.

I had the opportunity to interview Dr. Dyllon Randall to further ask about the potential sustainability impact of this technology. He talked about being inspired by nature and utilizing biomimicry as “nature knows no waste:” nature is sustainable, and we should learn from that. In addition, he stressed the importance of education and publicity to create change in our communities, whether it's promoting alternative sustainable materials or policy change.

What inspired you to investigate not only the use of urine to create building materials, but to account for every step of the process so that nothing is wasted?

To be honest, my curiosity got the better of me. I wanted to know whether we could use the same biological process that creates solid materials, something that’s available in nature ,and whether we could use the urea that is present in urine to do the same thing. Once we showed that it was feasible, the idea was to focus on how to reduce the various waste streams that are generated and how to look at it differently, so that there is no waste.

How accessible are these ingredients? Is this technology of brick making something that can be done throughout the world regardless of access to technology?

For the study, we use lab-grade chemicals, but the core chemicals that you require—bacteria, urine, and things like that—are freely available. You find them in nature. You would just need to cultivate them in different regions. And then you would need any loose material (sand, plastic, etc.) and then cement the material into any shape you want. The technology as a whole is quite simple. Nature has been doing this for millions of years. What we are focusing on is the optimization of this process, essentially a perfect recipe, so that anyone anywhere in the world can use this recipe to ensure that whatever they make will result in strong enough material.

Does the bio-brick work in humid or cold climates? Once already formed, are there any environmental factors that would prevent it from being used around the world?

We haven’t tested the actual bio-brick in different climatic conditions, and I would imagine that it wouldn’t matter in which kind of climate it would be placed. It’s more about the manufacturing process we use to make the bio-bricks. For example, the bacteria do not like cold temperatures. Hence, it might not work in a cold environment. But I don’t think there are any environmental factors that would prevent it from being used all over the world because this is a very natural process that is widely available in nature. What we’ve just done is use one type of method to make this bio-brick, but nature has done it for a bunch of other things.


How can this project specifically help people in disenfranchised communities, directly or indirectly?

A lot of this work is focusing on the potential to create new economies in the sanitation space, but also looking at various waste streams and converting them into valuable resources. So there are various new employment opportunities for people who might not have jobs. There is also the opportunity to manufacture a wide range of materials. You could make so many other building materials and products from it. For example, because we are using urine, we can create fertilizer from this process in a much more sustainable manner. That can indirectly benefit multiple communities.


How do you see your work affecting the people of the world in regards to natural disasters stemming from climate change?

Essentially what we are doing is reimagining our sanitation system and the focus on associated water resources that are required for it. For example, the toilet you flush uses clean water which you can drink, but what happens when you go through a drought, like we went through recently in Cape Town, where we couldn’t flush our toilets or shower frequently? Can you imagine a future where that valuable resource is no longer available? We are imagining a future where we are not so reliant on flushing toilets and urinals that need water, especially during droughts or in water-scarce areas. This has a direct impact on climate change because as climate change worsens, water resources deplete all over the world. Is this a viable solution to provide a form of housing to everyone, regardless of race or economic stature? What role would the government need to play in order to make this a possibility?

It is definitely another option. This would simply be another brick, another building material. By the time we have perfected it, it would be no different than the capabilities of a conventional brick; the key difference is that it's manufactured in a much more sustainable manner.

As for the government, I don’t think we would need their involvement other than funding the kind of research and development to take on these kinds of projects. If we target sustainable processes that have a commercialization opportunity from that work, we could see the benefits from that.

There are also issues with legislation. For example, in South Africa, urine is treated as hazardous waste (which it isn’t) until proven otherwise. You have to apply for a license to show that whatever you’re making from urine is actually safe. I think long term that kind of legislation needs to change because it is a barrier to entrepreneurship, at least in South Africa. I’m sure the same can be said elsewhere.



Photo by Robyn Walker

Building materials are usually used based on what is cheapest for those paying. Do you think the bio-brick can be the more cost-effective option? Do you think that it’s possible to be economically viable?

Yes, because if we can’t do that, the whole project fails. It has to be done in a sustainable manner but it has to be cheaper, if not the same price as conventional bricks. Usually, the challenge is just economies of scale. Once you can show that the technology is feasible, your cost will decrease when you make large quantities of whatever product. Once you roll this out with a backing, say from the government, maybe they incentivize these kinds of approaches, you get the cost to substantially reduce, and then you can roll out more and additional people will buy and use them. It’s similar to solar panels.

You’ve mentioned in your lectures and writings the need for a paradigm shift, linguistically and practically, in how we consider waste. What concrete steps need to be taken by us as individuals to achieve this? What steps does the government have to take?

It all starts with education. When you start educating people. and if they share those views and end up adopting whatever technology you implement, you get the change you desire. Prior to making the bio brick, we would take four to five days to fill a 25-liter container with urine. When the news of the bio brick project broke, we had people coming from other buildings who wanted to donate their urine. When that happened it would take six to eight hours to fill the same container. It just shows you the power of education because once people are aware of these kinds of projects they are enthusiastic and want to be involved. I think that is critical to changing anything. Any kind of challenge we as a society face, where we need substantial shifts in our understanding of how systems work, [needs] education. The government can help with policy changes and incentivize these kinds of initiatives, such as a tax rebate for companies who use these alternative sustainable materials.

Ultimately, this process can reimagine the way we think about water and sanitation. In a world increasingly affected by climate change, with increased natural disasters, and water becoming an increasingly valuable resource, we are in dire need of a solution like this. A brick like this can not only be produced without releasing any CO2 emissions, but it can also create affordable and accessible housing alternatives. The work Dr. Randall and his students are doing at the University of Cape Town truly has the potential to change the world. Dr. Randall ended his lecture with this quote by Buckminster Fuller, stating,“Pollution is nothing but the resources we are not harvesting. We allow them to disperse because we've been ignorant of their value.”