In Aarhus, Denmark, potatoes, herbs and tomatoes grow in large PVC pipes. The scene is a VinylPlus®-supported project, that has collected partners amongst academics, architects, local authorities and industry, and that aims to establish sustainable food production with reused PVC building waste

Growing cities: the need for sustainable urban development

Urbanisation has highlighted a forthcoming, major challenge: how can we sustainably provide food to growing cities? We find an answer in urban agriculture. The Food and Agriculture Organization of the United Nations (FAO) estimates that today, 800 million people worldwide have taken on this innovative form of local food production. Its advantages could be cause for its popular use. Transport, packaging and land-use is minimised, which has a positive impact on the Earth’s climate. Growing one’s own produce also helps low-income urban residents save money on food purchases.

Better trade-off between SDGs

Usually, cities are built on prime agricultural land. This creates a potential conflict between two Sustainable Development Goals: SDG 2 and its aims to end hunger, achieve food security and improve nutrition and promote sustainable agriculture, and SDG 11 and its objectives of making cities inclusive, safe, resilient and sustainable.

Urban agriculture using PVC pipes contributes to a better trade-off between the two SDGs. Hydroponics, aeroponics, vertical farming and the other urban growth systems make cities more resilient and sustainable and can support development of green spaces. At the same it enables local food production that supports nutrition security and income generation.

PVC and urban agriculture – a perfect match

At the root of urban agriculture lies rigid PVC building waste. Discarded pipes and gutters are readily available and free worldwide, and PVC’s unsurpassed durability, water suitability and light weight have made it the material of choice for the do-it-yourself crowd and professional urban farms. For years, creative ideas combining crops and PVC building waste have sprouted across the globe. Also, virgin PVC is the preferred material for high-end urban agriculture systems: Lyon’s Refarmers grow vegetables using PVC for Michelin restaurants, and the Brussels-based project, Aquaponiris, uses PVC pipes to combine growing vegetables and fish farming in a self-sufficient system.

The Urban Agriculture project involves many partners

Now, with VinylPlus’ support, the Urban Agriculture project investigates whether a more systematic use of PVC building waste in urban agriculture is feasible. The project branches into the design and construction of PVC building waste prototypes, so as to scientifically evaluate sustainability potentials, and also establishes partnerships with local community centers, architects, local authorities, waste owners and PVC converters. Current partners include the PVC Information Council Denmark, architects Kåre Sølvsten and Maja Sønderskov, Professor Marianne Thomsen and PhD student Daina Romeo from Aarhus University, Nordisk Wavin, the City of Aarhus, Samskab Aarhus, Gallo Gartneriet, GroSelv and Skraldecafeen.

Watch the videos to learn more about the project.

Aarhus explores potential of urban agriculture

Aarhus actively explores the establishment of urban agriculture in big cities, as the municipality is greatly interested in the interaction between itself, business and civil society. It was therefore a natural step for the city to participate in the VinylPlus project, explains Christian Brødsgaard Eschen, Project Manager, City of Aarhus. "This project represents a very nice narrative of how businesses try to reuse their waste. When waste can be used for urban agriculture, it means that we consume less and that we reduce the climate burden," says Mr. Eschen. The climate benefits have already been confirmed by Aarhus University, that in a recent report concluded that “the reuse of PVC from construction to agriculture is a promising way of slowing the flows, one of the indispensable steps towards a circular economy […] By giving it a second life, the utility of the material is maintained and can provide additional benefits to people.”

Faced with solving the challenges of collecting the right PVC waste fractions suitable for urban agriculture, Mr Eschen highlights Aarhus’ waste redistribution centre, ReUse. "I think that it would be ideal if there was a similar exchange centre for PVC building waste where the citizens can come and pick up sorted PVC building waste, which they can use to build urban agriculture systems in their communities," says Eschen. He also sees potential in emerging social-economic companies for which unemployed citizens can work to manufacture and sell vertical growing systems, thus linking the circular economy to sustainable food production.

The circular journey of a PVC pipe

Urban agriculture with reused PVC pipes prolongs the life of the products before recycling, which contributes to climate and energy savings and enables urban farming for everyone.