Mohak Gupta – Development Alternatives

“The circular economy promulgates a systemic shift in how we produce and consume by decoupling economic growth from resource extraction.”
Mohak Gupta, Assistant Program Director – Resource Efficiency and Circular Economy, Development Alternatives

In light of growing pressures from indiscriminate resource extraction and consumption, mounting heaps of various kinds of wastes, and the looming challenge of climate change, circular economy approaches now offer sustainable alternatives for the construction industry. While on the surface, the circular economy model seems to solve waste management issues, at its core, it promulgates a systemic shift in how we produce and consume by decoupling economic growth from resource extraction.

Transitions in fundamental materials

In the construction sector of India, with building materials accounting for almost 40 per cent of the carbon footprint of a building in the form of embodied energy, technology transitions in the fundamental materials such as cement, steel, sand, and coarse aggregates can go a long way in enhancing circularity and decarbonisation benefits. For instance, the adoption of national standards by the BIS for Limestone Clay Calcined Cement (LC3), a new type of cement with a 30 per cent carbon reduction in the production process and the potential to use secondary resources, is a welcome step.

There is a significant push to transition to innovative building materials in India, but it is far from the needed scale. For instance, while there is a shift from polluting burnt clay bricks to alternatives such as fly ash bricks, AAC blocks, and other precast products, their uptake remains mostly restricted to larger urban agglomerations and varies significantly across states based on the respective regulatory and business landscapes.

Other industrial wastes, such as red mud and blast furnace slag, are finding use in geopolymers and aggregates. City governments riddled with huge quantities of construction and demolition (C&D) debris are looking for solutions; however, the implementation remains painfully slow, with only a handful of cities that can boast of functional C&D waste processing facilities. Experiments on utilising different wastes in construction are widespread, with waste thermocol used as insulation, plastic waste used to make bricks and roads, or as refuse-derived fuel (RDF) in cement-making, and textile waste finding utility in acoustic panels and insulation boards.

A lifecycle approach

There is a strong case to be made for the cross-sectoral utilisation of these secondary resources as reduced virgin resource use means reduced mining and emissions and production waste, and the construction sector gallantly proffers the capacity to absorb all such discarded materials. However, adopting a life-cycle approach in assessing these solutions is crucial to be cognizant of their end-of-life impacts and avoid unintended consequences. For instance, adding plastic waste to roads may inadvertently scatter it across hundreds of kilometres of road length, leading to microplastics leaching into the soil systems at a scale that is impossible to reverse or manage.

Creating an Enabling Ecosystem

Mainstreaming circularity requires concerted efforts from both government and industry to ensure responsible decision-making based on transparent data disclosures and robust certification mechanisms. Public procurement can really drive these technology transitions by aggregating demand while the supply chains for alternate materials mature and stabilise. This requires strengthening policy frameworks and regulations, combined with appropriate fiscal incentives and subsidies, which can create the enabling ecosystem to transform the market while also attracting institutional financial investments. From a future perspective, investments in research and development will be essential to innovate the materials and technologies of the future, particularly bio-based materials, such that the buildings and construction sector can truly become green, regenerative, and circular.