The state Coastal Zone Management Authority has given green signal to floor space index (FSI) of 2.8 for the redevelopment of Worli’s Shivshahi housing society, part of a Maharashtra Housing and Area Development Authority (Mhada) layout.

Based on thi index, the civic body authorized as much as 1.53 lakh sq m of total building area on the 12,452 sq mt plots, which is 9.9 times the plot size. The society currently houses 198 families in 12 buildings developed by Mhada in 1950.

This FSI-a ratio that determines how much can be constructed on a plot, allowed the developer, Wonder Value Realty, to build three towers. These include a 42 storey skyscraper to redevelop the families living in the society free of cost, and two towers, each 38 floors, to be sold in the open market.

The civic body, which controls the land, will earn just Rs 172 crore as premium from the developer. Mhada has skipped its share of built-up area-an estimated 650 tenements for economically weaker sections-as stipulated in its own September 2010 policy.

The developer’s should submit their proposal a month before its new policy came into force. The housing authority’s earlier policy was based mainly on premium payment scheme.

The premium which Mhada will receive would be shared with the BMC. The land was leased by the BMC to Mhada for 999 years.

Mhada has so far granted FSI of 1.65 with premium. But the society will approach environment ministry for CRZ clearance at their own risk and cost to procure FSI 2.8.

The 2.8 FSI is only for buildings declared decrepit and which fall under CRZ II. The construction authority declared the 12 buildings of Shivshahi dangerous and dilapidated in 2009, but the buildings were repaired and painted by the society barely three years ago.