Two-thirds of the world’s population is predicted to live in cities by 2050. With cities responsible for more than 70 percent of global greenhouse gas emissions, there is a need for a more sustainable approach to city design and planning.

A partner at an award-winning planning and design consultancy says the solution lies in ‘circular cities’, which are designed as living ecosystems that minimise waste, and reduce, reuse and recycle resources as much as possible.

Stephen Moore, an urban designer and city strategist at the Sydney’s Hatch RobertsDay says: “Cities operate under a linear model, whereby raw materials are used to create goods, which are then consumed and disposed of. Urban planners should consider shifting infrastructure, transport and building design to make them adaptable and stand the test of time.

“The design of our cities should also look to maximise happiness and minimise hardship and focus on creating great places that people will love and enjoy. At its core, the way we design a circular city is through the lens of people.”

Moore says urban designers and planners need a framework to create cities that prioritise people and the environment. He proposes four tactics to design a sustainable, circular city model:

Prioritise walkability and accessibility. Stephen believes that the design of most cities is causing half the population to lack independence and mobility. He suggests designing compact cities that are dense and mixed-use. Planners should redistribute road space to prioritise pedestrians and cyclists, introduce more green spaces, and bring amenities and jobs closer to neighbourhoods. This will ensure land is used effectively and puts people first – promoting better accessibility and walkability.

Introduce green infrastructure. A key component of the circular city is the ability to reduce waste. Green infrastructure, which refers to a network of environmental features and green spaces that provide a natural means of reducing heat, improving air quality and mitigating waste. Green infrastructure can include street trees, constructed wetlands and green roofs – roofs that are almost entirely comprised of vegetation. Moore says the lifespan of conventional flat roofs can be doubled with greening. In Berlin, for instance, some green roofs are estimated to last 100 years as they can better withstand weather, high temperatures and sunlight. Green roofs can also insulate buildings, regulate indoor temperatures and, therefore, reduce energy consumption.

Use data and technology and collaborate with communities. Technology and data collection are valuable resources that planners and designed could utilise to create a circular city. Stephen says data mining – analysing raw data to extract meaningful trends – can help inform planning decisions to increase the longevity of a design and its acceptance in a community.

Consider mobility. When designing circular cities, planners could focus on the modes of transport accessible to the community to reduce car dependency. Multi-modal mobility – incorporating different modes of public transport and innovations such as ridesharing into an integrated system – can assist with this.