Circular thinking is essential for the futureproofing of cities

Many city governments have realised that halting the effects of climate change cannot happen fast enough. Cities will have to adopt new policies to make them resilient enough to live with and recover from the effects of climate events. Innovative ideas and technologies will help create sustainable cities capable of supporting populations of the future. One area that is proving a growing concern is the increasing amount of waste in cities, especially waste generated by the building and construction sectors.

Future sustainability will depend on a more circular model, reducing environmental impacts while strengthening the built environment. Currently, the building sector is a major source of waste. The residential, commercial, and public buildings in developed economies remain responsible for 40 percent of solid waste generation and 30 percent of raw material use. Increased reuse and recycling of construction materials is a key component in developing future resilient cities.

Reframing the opportunities with efficient waste handling policies

In Europe and across the globe, new technologies provide a unique opportunity to overcome the renovation challenge. Adopting circular principles as part of the economic recovery is an attractive (if not vital) approach for ensuring future sustainability. Placing renewed emphasis on designing waste out from the system at every stage of a building’s lifecycle brings tangible benefits.

By legislating the use of durable and recyclable materials, cities can benefit by:

• Reducing the amount of waste that ends up in landfills.
• Decoupling growth and development in cities from the use of raw materials
• Limiting the extraction of virgin materials required for new construction or renovation projects.
• Addressing the excessive levels of carbon emissions present in every step of the supply chain.

Increasing the recycling of materials used in building construction and renovation projects is vital for increased resource effectiveness and for reducing the waste challenge we as societies are facing. Sustainable development practices should continue to improve and be applied during the design, construction, occupation, maintenance, renovation, and final deconstruction of all buildings.

Supporting circular thinking in the building sector

A future that supports generations of human populations should now factor into most policy-makers decisions. Philosophical changes in societal considerations are becoming the norm, with some think tanks starting to look at concepts like a billion-year plan. Lofty ideals about future progress are futile if we do not address the current challenges and build the foundations that enable these philosophies. Developing a truly circular economy with a high degree of resource effectiveness is just as important as investing in state-of-the-art technologies and energy-efficient production techniques.

According to the World Business Council for Sustainable Development (WBCSD), building sector professionals are holding back sustainable practices because they lack understanding of the benefits and overestimate the real cost of green buildings. Sustainable construction may be associated with marginally higher start-up costs, but the operating costs compared to traditional buildings will be substantially lower due to their highly energy-efficient structures.

To accelerate the circular economy in the construction and manufacturing sector, national and city governments must support and facilitate the development of the needed infrastructure and help to create a demand by setting clear targets in large public tenders.

Improving the pathways to circular economies and increased resource effectiveness

Arup and the Ellen MacArthur Foundation are developing a credible tool on circular business models for the built environment. It aims to translate the principles of a circular economy into everyday built environment practices. The latest report supports cities and governments who have acknowledged that circularity can be an opportunity for them to add value and reduce waste in their economies.

By framing building circularity into five models, cities can realise the opportunities that currently exist from a more sustainable economic framework. The five models include:

• Creating flexible spaces that help maximise the use of current buildings.
• Turning buildings into flexible assets that can support more than one function during its lifetime.
• Deploying relocatable buildings for intermediate use or short-term applications with modular designs.
• Framing the lifecycle of buildings towards a residual value tied to the recoverable or reusable materials available during deconstruction.
• Enhancing procurement processes with a “product-as-a-service” model by linking subscription payments directly to a building system’s real-time performance.

Deploying these strategies will increase future sustainability by envisioning a future where building designers and owners maximise their investments and provide high-performing structures for occupants. The Arup-EMF model highlights the sources of lost value and provides tangible methods to address these concerns about circularity. 

Resource effectiveness in The Netherlands

Similarly, the city of Amsterdam in the Netherlands is focusing on downscaling the doughnut economic model for improved resilience and sustainability at the urban level. Keeping resource consumption within the planetary boundaries is an effective approach in reducing waste and maximising the useful life of natural resources.

Challenges to increased resource effectiveness at policy level

Accelerating the practices, processes, and policies that create circularity in cities starts with setting mandatory requirements and clear directions for markets and business sectors. Public authorities should integrate mandatory procurement rules to reduce waste, improve the recycling infrastructure and emphasise the reusability of construction materials.

Mainstreaming deconstruction practices, instead of traditional demolishing of existing buildings, provides a clear advantage that will support future resilience. Additionally, recovery and recycling of post-consumer waste generated during renovation or deconstruction initiatives will limit the number of materials ending up in landfills. Using policy to set the agenda for improving waste handling processes is the most effective way to ensure city governments can achieve their circularity goals.

Setting mandatory requirements that promote the reuse of building materials during deconstruction or demolition will force owners to overcome short-sighted interests. Building safer structures that consume fewer resources (both materials and energy) while reusing and recycling is by far the most efficient way of bringing circularity and resilience into the world’s building stocks.

Legislating circularity into waste handling in the building sector

Establishing a mandatory target for the share of materials to be reused during deconstruction and demolition projects will help to promote more resource effectiveness in the construction sector. Increased building renovation and well-planned deconstruction can help to decouple growth in cities from increased use of new virgin, non-renewable raw materials.

Designing for deconstruction is a useful step to improve future sustainability. Circular practices in the future will require a strategic approach from national and city governments to develop the infrastructure to handle the separation and collection of construction waste during deconstruction or demolition of buildings. These types of practices need to become mandatory requirements in the world’s cities.

The perception that landfilling construction materials as a viable development and renovation strategy will need legislative intervention, considering the lifecycle of the urban environment. Adopting and improving circular management principles at the city level will help protect the environment, the population, and the economy.

ROCKWOOL helps governments develop sustainable practices with waste handling in the building sectors using recyclable, circular materials like stone wool insulation.