Government estimates for construction and demolition debris did not change between 2000 and 2010, while the real estate sector expanded by 6-7% a year during the period
The divergent government figures prompted Delhi non-profit Centre for Science and Environment (CSE) to do its own calculation. It used data from three agencies. For calculating the amount of C&D waste generated in 2013, it used estimates by Technology Information, Forecasting and Assessment Council (TIFAC), a government of India agency. TIFAC says C&D waste generated during a new construction is 40-60 kg/square metre (sq m), during repairs is 40-50 kg/sq m and during demolition 300-500 kg/sq m.
For determining the built-up area, CSE used McKinsey & Company's report, which says the total built-up area in India in 2013 was 13.75 billion sq m. Of this, almost 1 billion sq m was constructed in 2013 alone. This would have generated 50 million tonnes of waste. Usually one-third of buildings get repaired every year. This would have added another 193 million tonnes of C&D waste. Assuming 5 per cent of buildings undergo large-scale restoration/demolition a year, these would generate 288 million tonnes of waste. The total adds up to 531 million tonnes. To estimate the area needed to dispose of this waste, CSE used calculations done by the Kasturirangan Task Force on Waste to Energy. The report says 400 hectares of landfill is needed to dispose of one million tonnes of waste. According to this formula, India would need a landfill of 8.65 million hectares by 2030 to dispose of its C&D waste.