what does the floor area ratio tell you 
the floor area ratio accounts for the entire floor area of a building not simply the building s footprint unoccupied areas such as basements parking garages stairs and elevator shafts are excluded from the square footage calculation buildings with a different number of stories can have the same floor area ratio value every city has a limited capacity or limited space that can be utilized safely any use beyond this point puts undue stress on a city this is sometimes known as the safe load factor the floor area ratio is variable because population dynamics growth patterns and construction activities vary and because the nature of the land or space where a building is placed can vary industrial residential commercial agricultural and nonagricultural spaces have differing safe load factors so they typically have differing floor area ratios as well local governments establish regulations and restrictions that determine the floor area ratio the floor area ratio is a key determining factor for development in any country a low floor area ratio is generally a deterrent to construction many industries and specifically the real estate industry seek hikes in the floor area ratio to open up space and land resources to developers an increased floor area ratio allows a developer to complete more building projects and this inevitably leads to greater sales decreased expenditures per project and greater supply to meet demand examples of the floor area ratiothe floor area ratio of a 1 000 square foot building with one story situated on a 4 000 square foot lot would be 0 25x a two story building on the same lot where each floor was 500 square feet would have the same floor area ratio value a lot has a floor area ratio of 2 0x and the square footage is 1 000 a developer could construct a building that covers as much as 2 000 square feet in this scenario it could include a 1 000 square foot building with two stories consider an apartment building for sale in charlotte north carolina the asking price for the apartment complex is 3 million and it spans 17 350 square feet the entire lot is 1 81 acres or 78 843 square feet the floor area ratio is 0 22x or 17 350 divided by 78 843 