Purpose

The purpose of a floor area ratio standard is to address the proportionality of building size to lot size and allow variation in building form within the established building envelope.

Note that this document is intended to provide supplemental information, and not meant to replace Ordinance No. 7684

FAR standards apply to all:

  • Principal and accessory residential buildings in RR-1, RR-2, RE and RL-1 zoning districts
  • Principal and accessory buildings that are used as a detached single-family land use in the RMX-1 zoning district
  • Principal and accessory residential buildings in the RL-2 zoning district that are on a lot 8,000 square feet or larger that are not located within a Planned Unit Development (PUD), Planned Residential Development (PRD), or Planned Development (PD) unless identified in Appendix H of Ordinance #7684.

FAR is the ratio of the floor area of a building in relation to the area of the lot on which the building or buildings are situated.

To determine the maximum amount of floor area permitted on a property you need to know the lot size and zoning district for your property.

Lot Size<5,000 SF5,000 to 20,000 SF10,0001 to 22,500 SF>22,500 SF
RR-1, RR-2, RE, RL-1, and RL-20.62:1(Lot Size x 0.2) + 2,100(Lot Size x 0.122) + 2,8800.25:1
Lot Size<4,000 SF4,000 to 4,999 SF5,000 to 6,499 SF6,500 to 10,000>10,000 SF
RMX-10.74:1(Lot Size x 0.20) + 2150(Lot Size x 0.20) + 2320(Lot Size x 0.195) + 24500.42:1

*Accurate lot area, as determined by a surveyor, is recommended in all circumstances but may be required if proposed development is within 20% of the maximum allowed floor area.

Examples:

  • 7,000 SF RL-1 Lot
    • (7,000 x 0.2) + 2,100 = 3,500 SF
  • 4,900 SF RMX-1 Lot
    • (4,900 x 0.2) + 2,150 = 3,130 SF

Portions of buildings that count toward the maximum amount of floor area permitted includes:

  • The total square footage of all above grade levels measured to the outside surface of the exterior framing or to the outside surface of the exterior walls if there is no exterior framing.

  • Partially exposed lower levels contribute to the maximum amount of floor area proportional to the amount of the lower level that is exposed by more than 3’ measured above adjacent finished grade to the bottom of the framed ceiling above.

    Diagram displaying lower level floor area ratio example
    *Wall area A is partially exposed above grade by three feet or less. Wall area B is exposed above grade by more than three feet
    • Example: (Length of wall B) / (Length of wall A+B) = The percent of floor area calculated towards FAR.
  • High volume spaces contribute to the maximum amount of floor area permitted depending on the height of the space measured from the distance between the floor and the bottom of the framed ceiling directly above it.
    • Spaces 16’ or more are counted twice
    • Spaces 26’ or more are counted 3 times

    • Up to 150 square feet of a stairwell may be exempt from counting as a high volume space

      Diagram displaying high volume space components

Portions of buildings that count toward the maximum amount of floor area permitted does not include:

  • Rooms or portions of rooms that are six feet or less in height.
  • A room that is solely used to house mechanical or electrical equipment that serves the building, including heating, cooling, electrical, ventilation and filtration systems.
  • The stairway opening at the uppermost floor of the building.
  • Up to one hundred fifty square feet of a stairwell shall not be considered a high volume space subject to the requirements.

  • Window wells or door wells in partially exposed lower levels will not contribute to the maximum amount of floor area if the distance of the opening of the well is no more than four feet, measured perpendicular to the wall; the well does not exceed 5 feet in length measured parallel to the wall; and the cumulative length of all wells along any front, rear, or side yard doe not exceed twenty feet in length for each such yard.

    Diagram displaying window well components.
  • Accessory buildings in Historic Districts and associated with Individual Landmarks may be exempt if:
    • The accessory building contributes to the historic significance of an individual landmark or a historic district;
    • The accessory building was built during the individual landmark or historic districts’ period of significance;
    • Only that portion of the accessory building built during the period of significance is eligible for an exemption; and
    • The floor area subject to this exemption is added to another principal or accessory building on the same property and approved as part of a landmark alteration certificate pursuant to section 9-11-12, B.R.C. 1981.