A tool used for determining the maximum permitted building area on a given plot of land, the floor-area ratio (commonly expressed as a decimal or percentage) is calculated by dividing the total floor area of a building by the area of the lot on which it stands. For instance, a 1,000 square-foot building on a 500 square-foot lot would have a ratio of 2.0, or 200%.
This metric plays a crucial role in urban planning and development, regulating building density and influencing the cityscape. It is a key factor considered by developers when assessing project feasibility and by municipalities when formulating zoning regulations. Historically, these ratios have been employed to manage population density, prevent overcrowding, and ensure adequate light and air circulation within urban environments. Implementing this ratio can help preserve a city’s character, promote sustainable growth, and maintain property values.