Can we create “circular cities?”

In the developed world, we have a wealth of natural resources that are often only used once and then discarded. How can we reuse raw materials to extend the life cycle of our resources, and reduce waste?

In developed nations, we consume natural resources and pollute the environment far beyond the Earth’s capacity. If the world’s entire population lived the same lifestyle as Canadians, we’d need 4.79 planet Earths to support our consumption patterns, according to the Ecological Footprint accounting measure. Decoupling consumption of finite resources from social and economic progress must be a priority as we look towards a resource-restricted future.

479 Earths

It’s a challenging shift, since Canada has thrived for centuries on abundant resources, stunning natural environments and, more recently, flourishing urban centers. At present, natural resources fuel 17 per cent of Canada’s GDP, supply 1.82 million jobs directly and indirectly, and provide $236 billion or 47 per cent of Canada’s annual merchandise exports. With that in mind, is it still desirable, necessary and even possible to use less of the resources that keep our economy strong?

The answer is yes, and we can’t start soon enough. Current global production and consumption models are already unsustainable. Ninety billion tonnes of resources are extracted every year to meet society‘s demands, and that number is expected to more than double by 2050. The world’s population is likely to reach 9.7 billion by 2050, with around 3 billion persons moving from low to middle-class consumption. Total demand for limited resource stocks could reach 400 per cent of the Earth’s total capacity by 2050.

The way we value, consume and manage our resources must change to accommodate future populations, to protect the environment and to ensure a stable economy decoupled from resource market fluctuations. At the same time, it’s necessary to consider both the needs of the future, and the needs of today. How do we begin to implement more sustainable practices for tomorrow, without mass disruption today? A circular economy could be the answer.


The case for a circular economy

A circular economy is one that is restorative and regenerative by design, decoupling economic activity from the consumption of finite resources, and designing waste out of the system to close the loop.

The traditional (and in most places the current) model of consumption is linear, with a “take, make and dispose” lifecycle. We take materials from the Earth, process and adapt them, use them, perhaps reuse them while eroding their quality, and then they’re returned to the environment as non-biodegradable waste. In a circular economy, materials maintain their value longer, remaining at similar quality throughout multiple usage cycles to allow for adaptable, flexible products and assets. In some cases, materials may even increase in value throughout their lifecycle. For example, glass that has been so degraded through use that it cannot be recycled can be processed to form low-density balls that have high structural strength and can be used as road aggregate in place of virgin stone, sometimes at lower cost.

Circular economy graphic 1 EN

Cities are a hot spot for resource cycles, consuming up to 80 per cent of natural resources globally, producing 50 per cent of global waste and 75 per cent of greenhouse gas emissions. Can a circular economy approach be adopted in the built environment to make the most of the resources that already exist, and increase the lifecycle value of new resources? Absolutely, though the way it manifests varies due to the long lifespan of the materials once they’re locked in. Let’s take a look by revisiting conventional, linear lifecycle stages.


Redefining raw materials

We tend to think of extraction as the point when raw materials are harvested directly from the Earth. However, in a circular economy, “extraction” doesn’t necessarily require us to use virgin materials. Look at the options for reusing existing materials that might otherwise be considered waste, such as steel beams in buildings, timber, or even road aggregate. If Building Information Modelling (BIM) is used during design and construction incorporating “materials passports,” resources can be tracked and tagged with details including the lifespan, load and contents. For instance, a structural steel beam would be digitally tagged with all of that information, to optimize decision-making for use and re-use.

A great example is Superuse Studios in the Netherlands, which used Google Earth to identify industrial waste materials and used resource availability to shape their design. The final building, Villa Welpeloo, is made from 60 per cent salvaged material that would otherwise have been degraded or wasted. There are also companies making “raw” materials from unusual waste material: bioplastics created from animal byproducts, roads from waste plastics and “wood” from newspapers, though in most cases this prolongs rather than eliminates end of life.


Reconsidering use

Societal needs and demands change rapidly, making our urban assets unnecessarily obsolete, disused and prematurely at “end of life.” IKEA noticed this, and has started to lease furniture, as well as buying back and reselling used furniture to prolong its life and extend value. To limit wasted resources in the built environment, we can design using a modular approach to enable buildings and infrastructure to adapt and recycle of materials at end of life. Modular and flexible buildings may allow the use of a building to change over its lifespan, maintaining the value of that resource as it responds to changing needs. For instance, buildings designed with adaptable floor plates and fitting to allow for easy subdivision, interactivity and flexibility over time can prolong the building’s lifespan. Brummen Townhall, Netherlands, can be dismantled and relocated; it was also the first building to receive a materials passport.

If products and parts are created on-demand and on-site, construction methods may change for the better, and transportation and storage of materials, and generation of waste are dramatically reduced. Designing for deconstruction is a technique that aims to responsibly manage end-of-life buildings to minimize use of raw materials. In guidance from the US Environmental Protection Agency, it is observed that the value of a building “is not…the materials themselves, but in the functional traits of shelter and the like that they provide when assembled together. Because of this, these materials retain more value when deconstructed and reused than when recycled.” This could include fixings rather than welding for steel structures, interlocking sections, easily removable windows, and mechanical and electrical components, to cite just a few examples.


Rethinking end-of-life

In a city that has truly adopted a circular economy approach, a resource’s “end of life” is non-existent, though realistically it is dramatically prolonged; assets from roads to street lights are operated and maintained so that resources are used effectively and their lifespan extended. Buildings are refurbished or altered, adapting their use and operation to new needs. If we know what went into a building, it becomes a depot of resources, rather than a pile of demolition waste. Once resources do reach the end of their current cycle, a circular economy recycles them at their highest value back into the supply chain to circulate indefinitely. For example, some companies have started to develop road pavement materials made from non-recyclable waste plastic that would otherwise have been incinerated or landfilled. A smaller-scale, but not insignificant example is use of food waste from local businesses or residences for compost that can directly be fed back into local urban agriculture (which provides a wealth of benefits in itself).

Circular economy graphic 2 EN-FR


Closing the case for a circular economy

Preventing potential resource shortages and associated market fluctuations and supply chain interruptions could result in over US$4.5-trillion in global economic activity by 2030. We have a long way to go before we get there. There are businesses and countries, particularly in Europe, leading the way today, seeing the future trends as drivers for today’s actions. Canada has yet to see a comprehensive circular economy strategy that encourages the collaborations and new business models that have been crucial to the advancement of the circular economy in other regions. A mindset shift of stakeholders in all sectors will be the tipping point for change: policy and legislation must transform, and procurement and funding models will need to be structured in a new way. The creation and adoption of business models that support and facilitate a circular economy will revolutionize our resource cycles both today and well into the future.

A circular economy represents a systemic shift in the way we value resources. It presents opportunities to minimize environmental impact, generate business and economic progression, enhance social productivity and health, improve the lifespan and functionality of our built environment, and protect economies from volatile resource markets.

More on this subject