Printing houses with cow poop

Besides the housing crisis, there is a poo-problem in the Netherlands. The agricultural sector emits an incredible amount of nitrogen, which mainly comes from the feces of cows. Students Doris Hondtong, Miruna Vlad and Maxim Meijer got wind of this and presented a possible solution during the last edition Dutch Design Week: 3D printing houses with cow poop.

Getting Our Shit Together is a speculative research project that investigates how cow dung can be made into a 3d-printable mass to eventually be used as a building material for homes. This offers an answer to the nitrogen problem and the housing shortage; two issues that are related to each other.

The agreed limit of nitrogen in the Netherlands is already reached by the agricultural sector alone, which results in the postponing of construction projects that are crucial for the Dutch housing shortage. Hondtong, Vlad and Meijer used these findings to make the following computation: if cow dung is a problem for the housing shortage, can't we use that poo to build houses?

The idea of ​​3D printing with poop was born when they studied the cow. “A pooping cow is like a living 3D printer” is said in the promotional video of Getting Our Shit Together. The students collected cow manure from a local farmer and conducted various tests for resilience and firmness to eventually arrive at the perfect recipe consistent with poo, fillers and binding agents. This resulted in a mix of methylcellulose, sodium alginate and xanthan, with additions of calcium carbonate, tapioca starch and glycerine.

Given the dubious building material, it was difficult to find someone that would lend them a 3D printer, so the team built one themselves with the help of a YouTube tutorial. The team then personalized the software so that they could eventually print their first miniature poop house. The house was then presented during the Biodesign Challenge 2021 and the Dutch Design Week.

The poo-houses come with several benefits: they encapsulate nitrogen, only few materials are needed and they are cost efficient. And with an annual 53 million tons of cow dung, there is an abundance in materials. The students calculated that they could build about 1.5 million houses a year with Dutch cow dung alone. However, the problem is that the current project didn’t come up smelling like roses. Thus the next step for the Getting Our Shit Together team is to make this unique building material odor-free.