Fooling the space index: strategic densification of Mumbai

January 9, 2012 / By


Per the recent census of 2011, the Mumbai Metropolitan Region has over 23.5 million people. To house this population on the ground floor, assuming a household size of 4 and dwelling units of 900 sq ft per family which are laid wall to wall, we would need 121,384 acres of contiguous land. If all these houses are built facing the street (for access), providing a frontage of 20 ft to each unit, the total length of the street would be 35,606 kilometres!

Being the commercial capital, the city attracts not only migrants from all parts of India, but also has a high floating population which commutes to the city for work everyday. This high density calls for developments to be vertically stacked by design, with multiple functions layered one over the other. Still the case for increasing the Floor Space Index (FSI) in the city, which would enable more construction over the same land area, has always been met with stiff resistance on practical, sustainable and ethical grounds. Permissible FSI in South Mumbai is 1.33, while that in the suburbs has recently been increased from 1 to 1.33. Additionally, developers can purchase Transfer of Development Rights (TDRs) and construct up to a FSI of 2. However, this is low compared to global destinations, such as Singapore, New York and Hong Kong Island Urban Area, which have FSI of 5, 10 and 12 or above respectively within a radius of 10 kilometres from the city centre. What does this imply for Mumbai real estate?

Real estate developmental density in Mumbai has not kept pace with the growth in population density. Due to the huge pressure on its already scarce land resource, market forces have tended to circumvent the base FSI regulations and build more through ‘discretionary approvals’ in lieu of construction of civic amenities such as parking structures. Also, certain construction features, which were excluded from FSI such as balcony, flower-bed, voids and niches, were manipulated so that they could be utilised as habitable spaces post construction. These innovative circumventions of building regulations are nothing but ‘creative feedbacks’ by the industry.

Last week, the Government disapproved of these discretionary approvals for construction, and has come up with amendments in the Development Control Regulations. To increase transparency and remove layers of regulations, an all-in FSI calculation has been stipulated, which includes the FSI-free design features. In lieu of lost volume of construction, developers can build 35% extra (as Fungible FSI) by paying a certain premium to the Government. This could keep the construction volumes nearly the same, as developers used to overbuild nearly 25%-30% as FSI-free features. However, now, the developers would be more inclined to include this extra 35% as usable carpet area in the properties, resulting in better efficiencies in terms of carpet area to saleable area ratios. We could see more box-like residential towers which provide a maximum habitable area to the tenant, instead of lavish architectural projections such as balconies and other design features. It would also make the industry a level-playing field for developers, due to the purge in discretionary approvals.

The moot point to debate is: Is Mumbai building enough? Should FSI be increased from its current levels of 2 to 5 or 10? The issues are as much scientific and statistical as they are ethical. Some points to ponder:

• Strategic densification through a differential FSI regime based on micro-zoning instead of the current uniform FSI system is the key for balancing densities with infrastructure.
• Construction volume is directly dependent on the carrying capacity of developed infrastructure in terms of roads, water and power. Hence, permissible FSI can be mapped with projected completions of infrastructural projects, leading to zones or corridors of high-density development.
• Urban renewal should not be blindly incentivised by higher FSI, as it might lead to congestion in zones which have older properties.
• Strategic densification of suburban nodes could be explored as development of infrastructure is convenient at low-density locations.
• Premium monies collected for higher FSI should be compulsorily ploughed back through investments in infrastructural development.

Inline Feedbacks
View all comments
More on '' in 'India'

Talk to us 
about real estate markets.