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Health & Fitness

Floor Area Ratio (FAR) A Measure of Density

With the town Metro Station plan and the downtown redevelopment being discussed at length, we've been hearing the term FAR or Floor Area Ratio a lot lately. What does this mean?

With the town Metro Station plan and the downtown redevelopment being discussed at length, we’ve been hearing the term FAR or Floor Area Ratio a lot lately. What does this mean? It’s a measure of density.

“The floor area ratio (FAR) is the ratio of the total floor area of buildings on a certain location to the size of the land of that location, or the limit imposed on such a ratio.

As a formula: Floor area ratio = (Total covered area on all floors of all buildings on a certain plot)/(Area of the plot)

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Thus, an FAR of 2.0 would indicate that the total floor area of a building is two times the gross area of the plot on which it is constructed, as would be found in a multiple-story building.” (*)

OK sounds a little confusing?

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For simplicity, let’s say the lot in the illustration is a perfect square and 200’ on each side (little less than an acre). If a one floor building is built that covers the entire lot that would be an FAR of 1. If, as illustrated, a 4 floor building is built on ¼ of the lot that too is an FAR of 1. So, an FAR of 4 could be a 16 floor building on ¼ of a lot or an 8 floor building on ½ of a lot. It all depends on setbacks, desired green space, height restrictions, and local ordinances.

So, an FAR of 4 does not necessarily mean a 16 floor building. With creative architecture and some give and take on the amount of green space does provide some flexibility in the designs of any major project such as the Metro Station and Downtown redevelopment. If an “overall” FAR for a multi-lot project is allowed, then it is possible to “transfer” density from one lot to the other. This is a simple explanation of FAR and there are exceptions for certain types of buildings such as parking garages.

FAR is not as popular as it has been in the past and a new term “Form Based [Design] Code” is becoming more popular. “A form-based code (FBC) is a means of regulating development to achieve a specific urban form. Form-based codes create a predictable public realm by controlling physical form primarily, with a lesser focus on land use, through city or county regulations.”(*) FBC, I believe, should be what we use in our downtown redevelopment.

(*) Wikipedia definition

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