FSI Variations in Mumbai and Manhattan
Source: Bertaud (2018)
The above images compare Floor Space Index (FSI) — the amount of floor area that can be built on a plot of land — in Mumbai and in Manhattan, New York City.
FSI is largely uniform across Mumbai. Neither is it differentiated between commercial and residential areas nor is it linked to land market values. Additionally, although higher FSI near transit nodes is known to enable easy access to transport, Mumbai’s FSI does not increase closer to transit nodes.
By contrast, Manhattan’s FSI is more varied, with limits corresponding to economic activity. This results in higher FSI in the city centre, which is usually the central business district (CBD), and lower FSI as you move away from it. Higher FSI in CBDs with limited available land allows for taller buildings and less urban sprawl. This means that individuals can live closer to their workplaces.
While FSI limits were introduced with the twin goals of containing urbanisation and curbing densification, they have instead proven counterproductive to the functioning of cities and the agglomeration benefits that they yield. Uniform FSI limits also restrict the availability of developable land area, shooting up the price of land and hence cost of living in cities.
Discussing the implications of FSI restrictions and more, the new policy document by IDFC Institute, “Reforming Urban India”, outlines a set of recommendations that seek to address the systemic dysfunctions — in land markets, planning regulations, and governance structures — that hold our cities back.