According to a 2021 Food Waste Index Report by the United Nations, 17% of global food production goes to waste, becoming the third biggest source of greenhouse gas emissions. 11% of this waste is generated by households, not only contributing to the climate crisis, but also provoking large economic costs, biodiversity loss, and the rise of pollution levels at unprecedented rates. Therefore, considering the key role that architecture and design plays in providing more eco-friendly housing options, it is essential to adopt and enhance a more self-sustaining, zero-waste approach.

The Greenhouse

That is exactly the mission that Australian designer and activist Joost Bakker sought to explore in a Future Food System project located in Melbourne’s Federation Square. Inspired by the idea that all elements in nature are equally important, the 87 sqm house known as “The Greenhouse” is built from organic materials, runs on solar renewable energy, and acts as a completely interdependent ecosystem. Besides providing shelter, the three-story project has the capacity of growing its own food in an urban environment – with the use of fertile soil in the roof terrace and an aquaponics system, it can cultivate vegetables, fruits, herbs, fish, mussels, and snails. In addition, the house includes other sustainable features, such as a mushroom wall that uses humidity from the shower, recycled wine bottles for flooring, and a bio digester that converts kitchen scraps into methane, among others.

By adding all these elements, the eco-building became a successful real-life example of an entirely zero-waste system that also offers the possibility to permanently access nutrient-rich food at a lower cost. However, it is clear that this wouldn’t be possible without the use of innovative technologies that allow for all the waste generated in the building to be processed and re-used. Among them, the house required an alternative plumbing solution, considering that its construction, location, and nature-centered motive meant no traditional methods could be used.

A sustainable plumbing alternative

To meet the challenge of providing plumbing for a closed-loop sustainable home, a pump was needed to pick up waste from numerous fixtures in the kitchen, bathroom and powder room. This would then allow for such waste to be discharged to an onsite passive biological waste water treatment system. With those reasons in mind, Saniflo Australasia, a leader in the plumbing industry, provided a pump solution along with long-time client Zen Plumb.

Acting as a whole house solution for the Greenhouse, the Sanicubic 1 was selected due to its ability to grind and discharge waste from multiple fixtures – and in a wide range of situations. Apart from featuring a powerful 1500 watt motor, a high flow rate performance, and an IP68 waterproof rating, the pump’s flexibility with several inlets makes it ideal for self-contained cabins, studios, or projects like the Future Food System building.

Other Sanicubic 1 benefits include: an easily removable motor for maintenance, an external hard-wired audio-visual alarm, and a working temperature of 35°C (it can even handle up to 70°C in short periods).

So, how does it work?

Firstly, waste water drains into the left and right inlet connections, as well as the top inlets, which can be adapted to 100 mm or 40 mm pipes. While the water level inside the pump rises, the trapped air is pressurized inside the dip tube, activating the pressure switch above the tube and turning on the pump. The stainless-steel blades then grind the waste as the impeller eliminates the already liquefied waste and, simultaneously, the flow is discharged from the unit’s middle pipe and up to the sewer line. After pumping, a non-return valve prevents the waste from returning to the pump.

In this way, the beneficial application of a non-conventional plumbing solution in the Greenhouse demonstrates the importance of exploring sustainable, zero-waste products and technologies to incorporate in the architecture world. As we approach the possibility of constant food, energy, and water shortages in urban areas during a climate change era, self-sufficient homes in the middle of cities that take charge of their consumption, as well as the products that make this possible, is something that holds promising potential.