With massive urbanisation rates worldwide, it is essential that our built environment contributes to sustainable urban planning. Vivek Jaisree Mohandas and Henning Wilts outline how the concept of Circular Economy can be applied to the construction sector.
On 29 July 2019, the world observed “Earth Overshoot Day” – the threshold day wherein we have used up all natural resources for 2019 that can regenerate and sustain the earth within a year. As per the International Resource Panel 2019 report, the growth of infrastructure and increase in material living standards have led to an accelerated demand of resources – by 3.2 per cent each year between 2000 and 2017.
The fast-growing Asian economies of China and India are undergoing massive urbanisation. It is expected that the Chinese construction growth rate is set to slow but will be offset by the growth in India. In India, the sector is projected to grow 6.6 per cent annually. The Smart Cities Mission and Pradhan Mantri Awas Yojana (PMAY) / Housing for All by 2022 in India are gearing up for development, leaving an unprecedented imprint on resource availability.
In this context, the 2019 UNEP report on global sand shortage, with sand being a major component of the construction sector, is quite alarming. If future cities are envisaged to be built in the traditional linear way (take-make-consume-dispose), then the ambition to limit global warming to 1.5°C is going to be unachievable.
Circular Economy as an Enabler for Sustainable Urbanisation?
Rather than focusing on recycling and reuse, the “Circular Economy” (CE) aims for restorative, regenerative, and disruptive design. In construction, circularity means reconfiguring the supply chain according to criteria of environmental sustainability in order to address global resource scarcity and climate change.
Buildings designed “circularly” may adopt the principles of “Designing out Waste (DoW)” which includes reuse and recovery of materials, offsite construction (prefabricated/3-D-printed components), standardisation of components and practices, sustainable procurement practices, design for disassembly (DfD). This will make the built environment less resource intensive, climate neutral, less polluting and more resilient to the effects of climate change.
Do Circular Solutions Already Exist in the Indian Construction Sector?
Though India has not fully embraced CE in construction, new solutions are becoming popular as they are backed by regulatory standards, such as using recycled waste material like glass fibre reinforced gypsum (GFRG). Urban dwellers are also becoming more aware of resource shortages, and are trying to act responsibly, as can be observed in the cases of the “Recycled Waste house” (Navi Mumbai) and the “Kachra Mane/ Trash home” (Bengaluru).
The planned city of India, Chandigarh, welcomes people from all around the world to the Rock Garden. This garden is an epitome of art created by Mr. Nek Chand, who regarded waste as a treasure – a fine example of the application of CE principles in the Indian context.
Waste (rocks, stones, ceramics) to art and gardens in Chandigarh, India:
© Vivek Jaisree Mohandas
© Vivek Jaisree Mohandas
In addition, a successful large-scale Public Private Partnership (PPP), Design Build Operate Finance and Transfer (DBOFT), serves as a model for construction & demolition waste (CDW) management in Delhi (Burari) and Ahmedabad and processes CDW into various building products.
The EU-REI GIZ report (2018) on resource efficiency has vehemently expressed the need for integrating CE principles in future infrastructure development. This report was followed by the 2019 draft policy on resource efficiency by the government of India, which reiterated the need of circular thinking as well as the need for regulatory standards for the reuse of secondary materials.
Flexible Use of Built Environment Spaces
As urbanisation booms, built environment spaces need to be flexibly managed. Currently, 15 per cent of India’s office spaces remain vacant. It is necessary to utilise these spaces instead of building new infrastructure. It can be observed worldwide that repurposing existing infrastructure is cheaper and more effective than demolition and starting from scratch.
The reuse of Kolkata Town Hall (India), the repurposing of military bases into houses in Heidelberg (Germany), and the transformation of the Jaegersborg water tower into a housing facility (Denmark) are good examples for adaptive reuse. Repurposing a building for other functions (for instance, office spaces into apartments/hotels) often generates more market value than single-purpose buildings.
The Role of Digital Technologies and Disruptive Innovation in Construction
Sustainable construction can only be geared up by digital technologies and disruptive innovation. Digitalisation plays a central role in reinventing economic development through CE. Due to the resources they contain and their longevity, buildings are increasingly viewed as “resource repositories” or “material banks”. The growing popular concept of a passport-like digital document (“material passport”) for such “repositories” will help store the information on building materials ranging from bricks to fixtures. This will ease the renovation or deconstruction processes.
The combination of these passports and Building Information Modeling (BIM) before and after the construction ensures that these infrastructures retain their value. Such innovative models of construction also garner support from financial institutions. In the Netherlands, ABN AMRO has partnered with MADASTER for materials passports to promote CE practices within the construction industry. All these innovative methods help reduce demand of virgin resources for the construction sector.
How Should the Future Canvas of the Built Environment Look Like?
It is important to embrace an inclusive approach to the sustainable transformation of the built environment and to consider all the stakeholders in the value chain to make changes happen. This is only possible by changing systems through new ideas of design thinking, disruptive innovations like ‘material passports’, and new construction and business models like the flexible use of spaces. Making changes in terms of standardisation and overcoming several regulatory barriers is also important. The role of digital technologies in transforming the built environment is tremendous and can challenge the status quo. Emerging economies like India must also decide on defining the targets relevant to the building sector to combat climate change similar to the coordinated efforts of the European Union’s CE Package and Waste Framework Directives.