Floor Area Ratio (FAR), also known as Floor Space Index (FSI) or Floor Space Ratio (FSR), is a zoning regulation and urban planning tool used to control the density and intensity of development in a specific area. FAR is a numerical value that represents the ratio of a building’s total floor area to the size of the piece of land on which it is built.

Why is Floor Area Ratio important?

Floor Area Ratio regulations are set by local zoning authorities as part of a city’s master plan and zoning codes. The purpose of FAR regulations is to manage and control urban density and, ultimately, prevent overdevelopment. A higher FAR allows for more building area on a given piece of land, potentially leading to taller and more densely built structures. Conversely, a lower FAR encourages lower-density development.

For example, if a city has a FAR of 2 and a land parcel is 10,000 square feet, the maximum allowable total floor area for a building on that land would be 20,000 square feet (10,000 * 2).

Benefits of Floor Area Ratio

Floor Area Ratio regulations have an impact on the physical character of a neighborhood, affecting factors like building height, setbacks from property lines, green spaces, and overall urban aesthetics. FAR is primarily used to balance urban growth, infrastructure capacities, and the preservation of open spaces. Different areas within a city might have different FAR values based on the desired development goals for those areas.

Limitations of Floor Area Ratio

While Floor Area Ratio (FAR) is a useful tool for regulating urban density and development intensity, it also has limitations and potential drawbacks. For example, FAR doesn’t consider building heights, leading to tall structures with minimal open space and can potentially neglect contextual aesthetics of a neighborhood, hindering innovative designs.

How is Floor Area Ratio calculated?

Floor Area Ratio is calculated using the following formula:

FAR = Total Floor Area / Area of the Land.

Here is a breakdown of the components:

Total Floor Area: This refers to the sum of the floor areas of all the floors in a building, typically including both residential and non-residential spaces. It includes common areas like living spaces, corridors, stairwells, lobbies, mechanical rooms, etc.

Area of the Land: This is the total area of the land parcel on which the building is constructed. In other words, it’s the horizontal area of the land when viewed from above.