For all the vibrancy and glamour, Mumbai has a flip side: more than half of its population lives in slums. In the past two decades, it is the Slum Rehabilitation Authority that has built close to 10 per cent of the city’s expected houses. The western metropolis has one of the worst per-capita open space ratios anywhere. Yet, more than one lakh of its fully constructed apartments have been lying quietly in the unsold inventory of the real estate industry that was thriving till not very long ago.