Floor Area Ratio (FAR) is the single most important number in NYC development. It determines how much you can build on a lot — and understanding it is essential for developers, investors, and anyone evaluating a property's development potential.
What Is FAR?
Floor Area Ratio is the total floor area of a building divided by the lot area. A FAR of 2.0 on a 10,000 sq ft lot allows up to 20,000 sq ft of floor area. The building can take many shapes — a 2-story building covering the entire lot, a 4-story building covering half, or a 10-story building covering 20% — as long as total floor area doesn't exceed the maximum.
Maximum FAR by Zoning District
Each zoning district has a maximum allowable FAR:
- R1-R5: 0.5 to 1.25 (low density residential)
- R6-R7: 2.0 to 4.0 (medium density)
- R8-R10: 6.0 to 10.0 (high density)
- C1-C2 overlays: Commercial FAR typically 1.0-2.0
- C4-C6: 3.4 to 15.0 (major commercial districts)
- M1: 1.0-5.0 (manufacturing)
Unused Development Rights (Air Rights)
If a building uses less than the maximum allowed FAR, the difference is called unused development rights or "air rights." For example, a 2-story building with FAR 1.0 on a lot zoned for FAR 6.0 has 5.0 FAR of unused rights.
These rights have real value. They can be:
- Built upon: Add floors to the existing building
- Transferred: Sold to adjacent lots (merger) or across streets in certain cases
- Used for zoning lots: Combined with adjacent properties for larger developments
Zoning Bonuses
Several mechanisms allow buildings to exceed base FAR:
- Inclusionary Housing Bonus: Developers can receive 20-33% more FAR by including affordable housing units (mandatory in some districts, optional in others)
- Community Facility Bonus: Additional FAR for including community facility uses (schools, healthcare, etc.)
- Plaza Bonus: Extra FAR for providing publicly accessible open space (less common now)
- Transit Bonus: Additional FAR for subway improvements in certain districts
Mandatory Inclusionary Housing (MIH)
In areas rezoned since 2016 with MIH, developers MUST include affordable housing to receive the full allowed FAR. Options typically include:
- 25% of units at 60% AMI
- 30% of units at 80% AMI
- Various deep affordability options
Analyzing Development Potential
Use RegWatch's free zoning lookup to check any property's zoning district and lot area. The full platform calculates available FAR, unused development rights, and applicable bonuses — essential intelligence for evaluating development sites. sign up free for complete zoning analysis.