What is FAR (Floor Area Ratio) and how does it impact usage?

FAR (Floor Area Ratio) is a critical zoning metric that governs the maximum allowable building size on a parcel of land. It directly impacts how much usable or leasable floor space can be developed relative to the size of the lot.

Here’s a detailed explanation of what FAR is and how it influences land use, building design, and development potential:

Definition of FAR (Floor Area Ratio)

• Floor Area Ratio is the ratio of a building’s total floor area to the area of the parcel of land it sits on
  
• Expressed as a simple number (e.g., 0.5, 1.0, 2.5, etc.)
  

Formula:

FAR = Total Building Floor Area / Total Lot Area

Example:

• Lot size = 10,000 sq ft
  
• Allowed FAR = 2.0
  
• Maximum allowable floor area = 10,000 × 2.0 = 20,000 sq ft
  

This floor area can be built over multiple stories, as long as other zoning requirements (like setbacks, height limits, and lot coverage) are met.

Impact on Usage and Development

Controls Building Density

• FAR sets a ceiling on how much building space can be constructed, affecting the intensity of land use
  
• High FAR allows larger buildings, suitable for commercial towers or mixed-use development
  
• Low FAR supports lower-density uses, like single-story retail or suburban office parks
  

Influences Building Height and Form

• A high FAR may be achieved by vertical development (multiple stories)
  
• Developers can adjust the building footprint vs. number of stories based on parking, open space, and design needs
  
• FAR often works in tandem with height restrictions and setback rules
  

Impacts Market Value and ROI

• Higher FAR typically increases the value of the land due to greater development potential
  
• Maximizing FAR can enhance the return on investment (ROI) through more leasable or saleable area
  
• Land with unused FAR capacity may attract investors seeking to add floors or build up
  

Affects Use Mix and Zoning Compatibility

• FAR allowances vary by zoning district (e.g., commercial, residential, industrial)
  
• Mixed-use zones may allow a higher FAR if the building includes public amenities, green space, or affordable housing
  
• In some cases, developers may purchase transferable development rights (TDRs) from neighboring properties to increase FAR

Local Variation and Regulation

• FAR regulations are set by the local zoning code or municipal development ordinance
  
• Certain overlay zones (e.g., transit-oriented development or downtown revitalization zones) may grant bonus FAR in exchange for specific community benefits
  
• Municipalities may apply different FAR limits to different sections of a lot (e.g., corner vs. interior)

Example Scenarios

Commercial Lot (FAR 2.5)

• Lot: 20,000 sq ft
  
• Max floor area: 50,000 sq ft
  
• Could allow:
  
  • A 5-story office building at 10,000 sq ft per floor
    
  • A 2-story shopping center with a larger footprint
    

Residential Lot (FAR 0.5)

• Lot: 10,000 sq ft
  
• Max floor area: 5,000 sq ft
  

Allows for a single-family home or duplex with limited expansion