Floor Area Ratio

The Floor Area Ratio (FAR) or Floor Space Index (FSI) 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.

The Floor Area Ratio is the total building square footage (building area) divided by the site size square footage (site area).

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

Thus, an FSI 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.

=Floor Area Ratio in zoning=FAR=

The Floor Area Ratio can be used in zoning to limit the amount of construction in a certain area. For example, if the relevant zoning ordinance permits construction on a parcel, and if construction must adhere to a 0.10 floor area ratio, then the total area of all floors in all buildings constructed on the parcel must be no more than one-tenth the area of the parcel itself.

A builder can plan for either a single-story building consuming the entire allowable area in one floor, or a multi-story building that rises higher above the plane of the land, but which must consequently result in a smaller footprint than would a single-story building of the same total floor area. By combining the horizontal and vertical limits into a single figure, some flexibility is permitted in building design, while achieving a hard limit on at least one measure of overall size. One advantage to fixing this parameter, as opposed to others such as height, width, or length, is that floor area correlates well with other considerations relevant to zoning regulation, such as total parking that would be required for an office building, total number of units that might be available for residential use, total load on municipal services, etc. The amounts of these things tend to be constant for a given total floor area, regardless of how that area is distributed horizontally and vertically. Thus, many jurisdictions have found it uneccessary to include hard height limitations when using Floor Area Ratio calculations.

Japan has extensively adopted the Floor Area Ratio in the zoning system since 1970. The evaluation of the adoption is, however, controversial: somewho say that it has deteriorated the skylines and building lines in Japanese cities; otherswho claim that it has protected the residential environments.

Andres Duany, 2000, notes 1) abdicating to floor area ratios (market forces) is the opposite of aiming a community toward something more than the sum of its parts. 2) FAR, a poor predictor of physical form, should not be used when the objective is to conserve and enhance neighborhood character. Whereas traditional design standards (height, lot coverage and setbacks or build-to lines) enable anyone to make reasonably accurate predictions, recognize violations, and feel secure in their investment decisions. And lastly, 3) if FAR is carelessly combined with traditional setbacks, assembled lots have a considerable advantage over individual lots, which has a negative effect on fine grained cities and the diversity of ownership.


* Meriam, Dwight (2004). "The Complete Guide to Zoning". McGraw-Hill. ISBN 0-07-144379-7.Area Ratio is the cross reference between two figures after they have been divided by the denominator of the previous shape.

External links

* [http://www.carfree.com/far.html An explanation of the Floor Area Ratio]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Floor Area Ratio - FAR — The total square feet of a building divided by the total square feet of the lot the building is located on. FAR is used by local governments in zoning codes. Higher FARs tend to indicate more urban (dense) construction. Buildings of varying… …   Investment dictionary

  • floor-space ratio — /ˈflɔ speɪs ˌreɪʃioʊ/ (say flaw spays .raysheeoh) noun a ratio of the maximum area on a site which may be built on, to the total area of the site; plot ratio. Also, floor space index …   Australian English dictionary

  • Area 51 — This article is about the U.S. Air Force installation in Nevada. For other uses, see Area 51 (disambiguation). Area 51 …   Wikipedia

  • Thessaloniki Metropolitan Area — and social ills.Thessalonians usually refer to 13 municipalities and one community as the City of Thessaloniki (or the Thessaloniki Urban Area); this is an urban area. However, this article focuses on the metropolitan area, that is a large… …   Wikipedia

  • Residential area — Within a urban area there is a tendency for land uses to aggregate. A residential area is a land use in which the predominant use is housing. Housing may vary significantly between, and through, residential areas. These include single family… …   Wikipedia

  • Silver ratio — The silver ratio is a mathematical constant. Its name is an allusion to the golden ratio; analogously to the way the golden ratio is the limiting ratio of consecutive Fibonacci numbers, the silver ratio is the limiting ratio of consecutive Pell… …   Wikipedia

  • Kiski Area School District — Kiski Area School DistrictDistrict typePublicReligious affiliationNoneLocationVandergrift, Pennsylvania, USAEnrollment 2006 2007Approx. 4,800 studentsGradesK 12District locationruralDistrict MascotCavalierDistrict colorsGold, White …   Wikipedia

  • Mechanicsburg Area School District — Address 100 E. Elmwood Ave, 2nd floor Mechanicsburg, Pennsylvania, Cumberland …   Wikipedia

  • Capital Area Transit (Harrisburg) — Capital Area Transit Founded 1973 Headquarters 901 North Cameron St. Locale Harrisburg, PA Service area …   Wikipedia

  • North Iowa Area Community College — Coordinates: 43°09′25″N 93°07′55″W / 43.157°N 93.132°W / 43.157; 93.132 The North Iowa Area Community College (commonly known …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.