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FSI or Floor Space Index means the area of construction allowed on a particular plot of land as per the Development Control Rules. In Mumbai, the permitted FSI varies in various locations depending upon the land and type of existing residence whether a Slum, Tenanted, MHADA, Cluster or a Co-operative Society and also the projects to be redeveloped.

As per Development Control Rules 33(7) of Mumbai, in the case of cess building, every tenant who is having less than 300 sq ft carpet area shall be given minimum of 300 sq ft ownership flat and the tenants having 300 to 753 sq. ft area, the existing area. Any area above 753 sq. feet will not be granted to the tenants.

Of course, the maximum ceiling was 2.5 Floor Space Index (FSI) under this category of buildings. Many of the old buildings in areas like Girgaum, Grant Road, Parel, Byculla, Dadar were not becoming viable under the above rules and therefore, the government took a decision to increase the same to 3 FSI. This has now encouraged the landowners and developers to come forward and redevelop such buildings.

For information, the cess building is one where the landlords of tenanted buildings do not care to maintain the same in case of need, have been taken over by the Mumbai Repair and Reconstruction Board for maintenance by charging a nominal amount as repair cess every month.

In case of redevelopment of plots under the above category, the builder gets incentive FSI of 50% or 60% of FSI over and above the FSI consumed to re-house the existing tenants. In such cases FSI goes beyond 6 or 7. There is no limit. For MHADA layout, the FSI is 2.5. In case of projects approved by MMRDA in Mumbai Metropolitan Region other than Mumbai under Rental Housing Scheme, the FSI allowed is 4.

In other words, now in suburbs, private buildings will get 2.7 FSI including fungible and in cess buildings and slums FSI of 4.05 (335% of 3) including fungible will be available. The fungible FSI now can be included in the flat and thus the area of the flat will go up. Therefore, redevelopment activities are in full swing with every other building surrounded by tins.

Further, under the amended DCR effective from 06/01/2012, a developers will be getting fungible FSI of 35% free of premium to the existing tenants and on sale portion 35% fungible FSI by paying a premium. The fungible FSI can be included in the flat and thus the flat area can be further increased.

The existing flat owners and in the other redevelopment like slum, cess buildings etc, the existing tenants will be given fungible FSI for construction free of FSI and on the sale portion, the developer has to pay the premium of 60% of the Ready Reckoner Rate for residential construction area of Fungible FSI and for commercial 80% of the Ready Reckoner Rate as the premium.

With regard to the FSI allowed for slum related projects, the Slum Rehabilitation Authority (SRA) has declared certain areas occupied by slum as the land on which SRA scheme can be redeveloped in which the existing occupiers in slum gets 269 sq ft carpet area free of charge with a restrictive clause that they should have been settled in such slum before 1995. There is a proposal to relax the said clause that the term of settling down in such slum may be extended to 2000. However, the confirmation to this effect is awaited.

The State Government has formally increased the floor space index (FSI) for slum rehabilitation projects from 2.5 to a maximum of 4.

The state urban development department issued a notification under section 154 of the Maharashtra Regional and Town Planning Act (MRTP), 1966 stating that projects involving all high-density slums-those having over 650 tenements per hectare-are entitled to an FSI of 4, whereas those with lower tenement density are entitled to 3. Senior officials from the Urban Development Department said that the notification highlights that all procedural formalities concerning the higher FSI move are now complete.

FSI is a development tool that determines the extent of construction permitted on a plot. It is a ratio of permissible built-up to the total area of the plot. A higher FSI would allow developers additional construction on slum land. As per the notification, approvals for redevelopment projects with higher tenement density will be cleared by the state government. The Slum Rehabilitation Authority retains powers to approve schemes with lower tenement density.