“Depending on how the study reviews FSI use in the city, we will make necessary amendments to the Development Control Rules,” said TC Benjamin, principal secretary for the state Urban Development department.

Madan added that the study will take a look at FSI usage in cities such as Singapore, New York and Seoul. “The norm for residential FSI across most cities if 0.5 to 4 depending on factors such as size of apartments. In case of bigger apartments, more FSI is granted considering low density in the area. For commercial districts the FSI is as high as 10 to 25,” said Madan.

Developers in Mumbai have for long being demanding higher FSI in order to correct the demand-supply mismatch.

“Where even cities like Chennai and Hyderabad have a high FSI of 2.5, Mumbai was too conservative in its FSI policy. A differential FSI hand in hand with infrastructure development is a good idea. However with most projects in Mumbai being redevelopment projects, there won’t be an immediate decrease in prices unless there is government intervention on resettling existing tenants or clear land titles as in the case of Dharavi,” said developer Mayur Shah from the Marathon group.

Urban planners have welcomed the move albeit with some reservations. “Cities should be planned with varying FSI, like high FSI for low density higher income group colonies or low FSI to protect historic areas like Khotachiwadi. But any such study on FSI should also address the issue of affordable housing and infrastructure development through some regulatory mechanism,” said Anirudh Paul, director, Kamala Raheja Vidyanidhi Institute of Architecture.