As Mumbai contemplates plans to extend its cluster model to the suburbs and satellite towns, the city’s municipality commissioned urban researchers from the National Environmental Engineering Research Institute (NEERI) to assess the cluster model titled “Urban Renewal Scheme” (URS). The URS involves reconstruction and redevelopment of buildings on extensive areas using an incentive floor space index (FSI). The study came out to advise against the scheme in the suburbs since it will densify the city even more and may impact its overall liveability index. The plan to extend the cluster model to the suburbs and satellite towns was first raised by the previous government in 2014, but was halted by the Mumbai High Court, which ruled against implementing the plan in these areas until a detailed study on its ramifications was conducted – which brings Mumbai to the recent study by NEERI.

Mumbai is already the fifth most tightly packed city in the world; an average of 25,984 people share 1 square kilometer (0.62 square mile). If the URS will make it even denser, then the study came just in time to put an end to the government’s plans and persuade them to divert to an alternative solution.

“The suburbs of Mumbai do not fit in the classical model of suburbs and are fairly dense habitations. The additional FSI and the mode of its application [under URS] mean that the URS areas will increase in density. There is a considerable debate on the impact of densification and overcrowding on the social and mental life,” the report reads.

Regardless of their age and structural condition, the report elaborates that the high incentives given for the URS may encourage a trend to abolish repairs and encourage demolition of existing constructions. Moreover, the scale of new construction will take its toll on the affordability of housing and rental prices in proximate areas. Thus it can affect the liveability of the city and may lead to long-term un-sustainability.

In conclusion, the report recommended the government lower FSI incentives for builders. The NEERI researchers requested that the municipality ensure that new occupancy in the additional living space is restricted to 40%. They have also suggested that the government moderate the process for identifying and defining a cluster. In response to the NEERI report’s findings, the FSI will now be capped at 3, after the government had initially planned to replicate the model in the island city, offering 4 FSI to builders. Also, the minimum size of a cluster for suburbs will be 6,000 square meters (3,728 square miles).