Report: Going circular – a vision for the urban transition

Why go circular?

The urgent need for climate action and circularity as climate action
Although the problem of global warming has been known for more than 30 years, it has not been challenged to any significant effect. In fact, carbon emissions caused by human activities have increased constantly, resulting in a continuing rise in carbon concentration levels in the atmosphere.

Our biodiverse ecosystems are under threat, and we see that the effects of climate change are also having a significant impact on human society. Decisions made about cities and urban infrastructure in the next decade will put countries on a path to prosperity and resilience – or decline and vulnerability. As the United Nation has stated, we need to reduce emissions by 7.6% every year between 2020 and 2030 to limit global warming to 1.5°C.

The aesthetics of circularity

Circular strategy is an applied mindset that follows the principles of nature. In this regard, circularity means adapting any human construction to the site-specific processes of nature. This aesthetic framework provides scope to prioritise beauty and the creation of places we strive to take care of in the future.

This illustration shows how architecture and engineering students explores current social issues and future solutions. The students envision a potential use of environment on top of the railway tracks. Sweco Norway in collaboration with the estate developer Aspelin Ramm.

Circular urban design

From a circular perspective, it is important to see the urban structure as a whole – which requires more visionary, holistic planning. Implementing a circular approach is crucial to reducing carbon emissions in the construction sector.

The circular design of our cities involves managing the physical environment within the site-specific processes of nature. But how does this relate to how we design our cities? And what’s in it for the citizens?

In 2020, the EU published a Circular Economy Action Plan. This plan provides a future-oriented agenda for achieving a cleaner and more competitive Europe in co-creation with economic actors, consumers, citizens and civil society organisations According to the Circular Economy Action Plan, the circular economy will provide citizens with high-quality, functional and safe products that are efficient and affordable, last longer and are designed for reuse, repair and high-quality recycling.

A whole new range of sustainable services, product-as-service models and digital solutions will bring about a better quality of life, innovative jobs and upgraded knowledge and skills. When we consider models of circularity, we have to adapt and understand them in the context of urban design.

On the image is a value-driven visualisation of the Ströms building in Gothenburg based on its carbon footprint from its whole life. Visualisation tools can be crucial to point out circularity aspects such as the reuse, recycle, and upcycle potential.

Circularity

Circularity involves recycling, reducing, reusing, producing and sharing, and more. However, this report focuses on physical structures and their surroundings. Other key issues, like social and economic considerations, mobility and energy production, are integral though not addressed specifically here.

Key definitions

• Carbon Shorthand for all greenhouse gases, quantified in tonnes of carbon dioxide equivalent (tCO2e)
• Downcycling When materials are is recycled into another material of lower quality.
• Recycling When materials are processed into products or materials used for their original or other purposes.
• Upcycling Recycling materials into new products or materials of better quality.
• Aesthetics Visual and sensory qualities and the citizen’s reflections upon such qualities.

Circular actions

As a result of creating materials for use in construction, emissions are in many cases at least as large as for energy use throughout the building’s life cycle. The EU stipulates that starting in 2020, 70% of all construction waste must be recycled.

The built environment

Buildings are an essential part of our living environment and provide space to work, socialise, sleep, or simply enjoy life. Building structures, walls, roofs and floors are resources that enable these operational environments. However, as time goes by, cities and districts evolve. Buildings need maintenance, people move in and out and grow older, and new generations present different needs.

As a result of creating materials for use in construction, emissions are in many cases at least as large as for energy use throughout the building’s life cycle. The EU stipulates that starting in 2020, 70% of all construction waste must be recycled. It is crucial that we constrain all actions that escalate climate change. We must realise that each brick, wall, door and windowpane have a value.

In the UK, White City Place, a project made up of 6 buildings of 950,000 sq.ft. on 17 acres of land, was awarded a BREEAM (sustainability assessment) ‘Excellent’ rating. The rating recognised the way in which the 3 existing buildings were transformed into modern working environments through refurbishment and repositioning.

Reusing existing buildings

Preserving and extending the lifetime of existing buildings results in less carbon emissions than demolishing and building new ones. To reduce emissions created during the production of building materials, existing buildings should be reused where possible and space efficiency maximised to avoid building more.

In the Økern area development in Oslo, an 18-storey building from 1970 is planned to be reused in the future. If the building is demolished, and a new one rebuilt, the materials will account for approximately 4,000 tonnes of carbon. By contrast, preservation and rehabilitation, which retain most of the heavy structures, will emit about 1,900 tonnes of carbon. This contributes to a reduction in emissions of approximately 55%.

Reusing building elements

When the entire structure cannot be adequately reused, reusing existing building elements makes a good alternative. Global cement production is responsible for approximately 5% of total carbon emissions. This is more than the global emissions from air travel.

A positive example of the potential extensive reuse of building materials and elements is Construction City, an alliance of construction businesses in Ulven, Oslo. The project has an opportunity to reuse, or recycle, 70–90%. They have the potential to reuse 3,400 tonnes of concrete by reusing and reconfiguring elements, and as a result reduce overall carbon emissions by 952 tonnes. This is the equivalent of about 350 round-trip flights from London to New York.

Recycled and biobased materials

To reach carbon neutrality targets, we need to find ways to produce buildings with minimal carbon emissions and to maximise operational energy efficiency during the use phase.

In addition to the reuse of existing materials, the construction of buildings using renewable materials offers a decent solution in this regard. Building in wood has gained much attention recently. Wood is renewable, can provide large separate components to build with and is relatively light. This allows for a rapid construction process and less need for large cranes.

Mjøstårnet, construction design by Sweco Norway. The tallest wooden building in the world. Generally, up to 50% carbon is saved by building in wood compared to conventional construction. Photo: Sweco

Designing for reuse

The reuse of existing buildings is another method that prefers reuse over new builds. Entire buildings can be moved from one site to another.
Norway has a long tradition of moving its houses. In fact, the dismantling and rebuilding of log cabins in new locations is part of Norwegian building history. In the future, when designing new buildings or structures of various kinds, the same principles should be taken into consideration.

Today, solutions already exist to make movable buildings. Parts of buildings can be detached without destroying the main structures. Elements of lightweight wooden structures are quick to assemble on site and can then be moved somewhere else or even implemented as a part of another building. A good example of this modular design is by a Finnish building supplier that provides prefabricated learning spaces that can be dissembled and moved to another site when needed. Schools, kindergartens, gymnasium and cantinas are made like this.

Design for local drainage and the establishment of floodways. One consequence of climate change is increased and heavier rainfall. In areas where much of the land is covered by pavement and buildings, water runs off as much as 10 times faster than on unpaved land. Creating rain gardens that manage the water locally is one way of meeting the challenges.

In order to let water follow the cycle of nature, it should be drained locally. This means designing for storage and delay on site, preferably in an open system to handle heavy rain and achieve a more robust system than leading the water into pipes.

The principles of a rain garden. Illustration made after principles by Göteborg Municipality, Sweden

Reusing water on site

In areas where water is a preciously limited resource, cleaning and reusing water is crucial for ensuring adequate supplies.

Biozone Ootmarsum in the Netherlands is a constructed wetland whose main purpose is to convert the effluent from the wastewater treatment plant of several towns into clean water that can be used in the natural environment. The project, designed by Sweco, is a part of the European Union Interreg IIIB project Urban Water Cycle.

The biozone adds oxygen to the water and reduces ammonium and suspended matter. The biozone has varying water depths containing both aquatic plants and marsh plants capable of growing. This forms the basis of an aquatic ecosystem that is home to several vital ecological links.
Land use planning

‘Wise development’ is defined by the area we do not use, and by how we promote landscape qualities.

Wise land use planning shows great potential to reduce negative impacts on biodiversity, animal habitats, soil structures and other qualities of nature. ‘Wise development’ is defined by the area we do not use, and by how we promote landscape qualities.

Designing good landscape plans at an early stage make it possible to avoid unnecessary blasting, digging and transport. For every 5.5 cubic metres of rock blasted, one truck is needed to transport it.

At Kadettangen west of Oslo, Bærum Municipality developed a popular recreational area on top of new terrain built with about 21 million cubic metres of masses, mostly rocks, transported from a large infrastructure project close to the site. Photo: Siri Bjørnbakken

Circular considerations – The aesthetic impact of circular action

Circularity contributes to climate mitigation and adaption by both preventing and managing the consequences of climate change. It also adds a pleasing aesthetic dimension to urban development. In most cases when the concept of circularity is realised, it often results in a more interesting urban environment for citizens.

A circular point of departure results in site-specific solutions, and often the preservation of historic elements of the site concerned. Taking circular action is made visible to different degrees in the physical environment. Sometimes it is easy to see, such as when an old brick building is placed in a modern context. But circular actions are sometimes more difficult to perceive visually, for instance when a modular building has been erected, or elements of the terrain and vegetation have been incorporated into the new developed landscape.

What does this mean for the people who live in these areas? Circular action results in places with a more site-specific character and diverse visual expressions, where nature is made more visible and available in the urban environment. Simply put, circularity helps to create more attractive places that are more appreciated by citizens.

The Devonshire Square (UK) project shows the conversion of a previously used space. It includes the reuse of materials and the upgrade and reconfiguration of existing plant systems. Photos: Nick Clark

The transition to circularity

To succeed in the transition to a circular approach in developing urban environments, we need to recognise differences in the approaches. Every site has its own character defined by natural conditions and how these are managed over time. This means that every project requires individual assessment regarding solutions and design. However, as many good examples have shown, circularity is possible!

It is crucial that governments and other stakeholders ensure effective implementation. Laws and regulations must reflect the change and make it happen, and developers must include circularity as a part of their requests. We all have a role to play.

• Policymakers must set requirements while facilitating the implementation of circular practices by updating regulations.
• Estate developers must approach their projects with circular ambitions, but at the same time recognise the complexity of circular projects and the expertise that is needed to shed light on the decisions that need to be taken in every case.
• Architects and landscape architects must set circular goals and work out circular design concepts.
• Engineers must have the skills to evaluate the properties of different materials in terms of durability, suitability, longevity and quality, as well as to map waste streams in a project or an area with a view to reusing energy and materials.
• Educators must inform and prepare the next generation for the transition by educating around circular methods and mindset.

Illustration: The circular socity. Design by Sweco.