Could FSI be a Solution to the Urban [Affordable] Housing Problem?

Aparna Dua
Asha Impact: Profit, Purpose and Policy
4 min readMar 28, 2018


By Aparna Dua, Senior Manager and Venkatraghavan TT, Associate Asha Impact

The problem of urban housing shortage is a complex one. With limited availability of land and owing to rapid urbanization there is an increased pressure on a city’s resources and especially on the availability of affordable homes. Cities are expected to house nearly 40% of India’s population by 2030 and account for nearly 70% of India’s GDP by 2030[1]. Urban India has managed to attract investments on the back of robust growth, but has failed to offer a basic standard of living to its citizens. With this rapid pace of urbanization, cities are growing, many a times in an unplanned manner. Housing, and in particular ‘affordable’ housing is getting pushed to city peripheries or pockets that still lack basic amenities, trunk and social infrastructure. It is against this backdrop that the ongoing debate of whether FSI should be increased in cities becomes relevant.

FSI, also known as Floor Area Ratio (FAR), is the extent of buildable area allowed on any given plot. For instance, if a building project is given an FSI of 2, it means that on a 10,000 square metres plot, the construction can be up to 20,000 square metres, thus allowing it to go vertical. Similarly, on the same 10,000 square metres plot, if the builder decides to construct on only 5,000 square metres, the building can have four storeys (20,000 square metres) and thus open up the rest of the space for green areas and other social infrastructure. The height of a building has implications on construction costs and hence the price of the housing units, making spatial planning for a project a careful balancing act for the builder.

Earlier this year, the MHUA formed a committee to analyze upward revision of FSI, which could lead to an increase in the number of high-rises in Indian cities, where building bye-laws have until now imposed height restrictions. Proponents of an upward revision of FSI believe that India’s current ‘Malthusian’ urban policy has been reluctant to consider an increase in population as a sign of success and instead view it as a failure. A common argument to illustrate the rationale for increasing FSI is to take the example of Shanghai. In 1984, Shanghai had only 3.65 square meters of space per person. But by making liberal use of FSI, despite a large increase in population since 1984, the city had increased the available space to 34 square meters per person by 2010[2]. In contrast, in 2009, Mumbai on average had just 4.5 square meters of space per person. Further, given the scarcity of land in a city like Mumbai, restrictive FSI can result in limiting the supply of homes, thus inflating the price of homes and making them unaffordable. A progressive increase in FSI can serve two purposes:

  1. Increase in consumable floor space of households as incomes increase, resulting in lower densities in cities and
  2. It decreases a city’s sprawl thereby reducing the transport costs and carbon footprint per household.

These facts while true, only paint half the picture. Opponents argue that an increase in FSI will only increase the density in an already crowded Mumbai. Indian cities are already denser in comparison to other larger cities and going vertical may constrain the already strained infrastructure such as roads, parks, hospitals and schools. What is not (often enough) discussed is indoor crowding or number of persons/ built-up area. Table 1 indicates an example of overcrowding by comparing the example of Mumbai and NY — two cities with vastly different FSIs but similar densities. However, as plot sizes vary, it implies a person in NY enjoys 11 times the space a Mumbaikar does.

Similarly, other factors that need to be considered are the crowding of streets, schools, parks, hospitals and other amenities. This can be estimated by looking at the indoor crowding, FSI and ratio of buildable plot area to the street area (area for circulation of pedestrians and vehicles).

Table 1: A comparison of Mumbai and NY w.r.t. FSI, density and consumable space per person[3].

Thus, a blanket increase in FSI is simplistic in its approach. FSI is not our panacea but could help in opening up more livable space in cities if a more thoughtful and informed approach is adopted.

  1. FSI revisions should be considered on a location-by-location basis. Higher FSI for commercial areas and certain zones as is the case in many large global cities could be adopted. 2
  2. To counter the increase in density, an increase in FSI must be accompanied by minimum dwelling size restrictions.
  3. Increases in FSI must be accompanied with adequate investment in social infrastructure for a locality/ zone to avoid ‘crowding’ of amenities.

Someday, maybe the skyline of Mumbai and many other Indian cities will also be the muse of a skyscraper photographer!

[1] McKinsey Global Institute: India’s urban awakening: Building Inclusive cities , sustaining economic growth

[2] Alain Bertaud: Mumbai FAR/ FSI conundrum

[3] Housing, FSI, Crowding and densities: Handbook Vol. I