What is Floor Area Ratio (FAR)? Zoning Definition

How FAR Works

Floor Area Ratio (FAR) is one of the most important numbers in zoning because it determines the maximum square footage you can build on a lot. If you have a 10,000-square-foot lot in a zone with a FAR of 1.0, you can build up to 10,000 square feet of floor area. A FAR of 2.0 on the same lot would allow 20,000 square feet -- which you might achieve by building two full-size floors, four half-size floors, or any other combination that stays within that total.

Why FAR Matters for Property Buyers

When evaluating a property, FAR tells you the development potential of the land. A higher FAR means you can build more usable space, which directly affects property value. If you are buying a single-family home on a lot zoned with a FAR of 0.5, you know the house cannot exceed half the lot size in total floor area. If you are looking at commercial property with a FAR of 5.0, you are looking at a site that can support a mid-rise building.

Practical Considerations

• FAR does not dictate building shape. A FAR of 1.0 could be a one-story building covering the entire lot or a two-story building covering half the lot.
• Some areas are excluded from FAR calculations in many jurisdictions, such as garages, basements, and mechanical rooms -- but rules vary by city.
• Bonus FAR may be available if you include affordable housing units, public open space, or other community benefits.
• Always check your local zoning code for the exact FAR calculation method, because cities differ on what counts as "floor area."