What is the difference between buildable SF and existing SF?

Buildable square footage is the total floor area a property's zoning allows to be built — calculated by multiplying the lot size by the FAR for that zoning district. Existing SF refers to the habitable square footage of a standing structure.

How can I find out the buildable square footage of my property?

To find the buildable square footage of your property, multiply your lot size by the FAR assigned to your zoning district to get your maximum permitted buildable SF. A 4,000 SF lot in an R7A district at FAR 4.0 supports 16,000 buildable SF. Use NYC's ZoLa map to confirm your FAR, then have an architect verify the number after accounting for all bulk regulations.

If my building is as-of-right, can I build up to the full buildable square footage?

Yes, you can theoretically build the full square footage, provided your design also complies with all physical bulk regulations. A lot zoned for 40,000 buildable square feet might only support 30,000 square feet once lot coverage limits, height caps, and setbacks are applied. Property owners must hire an architect to run a zoning feasibility study to map out these exact physical constraints.

How is buildable square footage used in development site pricing?

Buildable square footage dictates a development site's revenue potential by determining the total allowable area that can be constructed. To calculate buildable square footage, divide the property's total purchase price by its maximum allowable gross floor area.

How does buildable square footage affect the value of my property?

Buildable square footage directly increases your land value by maximizing the total area a developer can legally construct on the site. A property with 20,000 buildable square feet and only 4,000 square feet built holds significantly higher development value than an identical, fully built-out lot. Property owners must calculate this gap between existing and allowable square footage to avoid underpricing their asset before a sale.

Is buildable square footage the same thing as air rights?

No — buildable SF is the total floor area permitted on your lot including what is already built; air rights is only the unused portion, the gap between what is permitted and what exists. A 20,000 buildable SF lot with a 5,000 SF building has 15,000 SF of air rights. Property owners can monetize this specific gap by selling or transferring these excess air rights to an adjacent lot through a zoning lot merger.

What other factors limit the amount of buildable square footage I can have besides FAR?

Lot coverage rules, setback requirements, and height limits can all reduce what is actually constructible below your FAR allowance. A lot with a FAR of 6.0 and a 40% lot coverage limit may only physically support a narrow tower rather than a full-floor building to the FAR ceiling.

If my lot is irregular how does that affect my buildable square footage?

Irregular lot shapes can reduce your usable buildable square footage by up to 30% by forcing stricter physical setbacks that shrink your actual construction footprint. A triangular or flag-shaped lot with a 4.0 Floor Area Ratio must still apply mandatory yard regulations on all sides, often leaving a smaller, inefficient building core. Property owners must secure a formal zoning analysis from an architect to determine exactly what is constructible on their site.

Is an open courtyard included in my buildable square footage?

No — open courtyards are not counted as floor area and do not consume your FAR, but the courtyard footprint counts toward your lot coverage calculation. If you enclosed a courtyard to create interior space, that new area would count as floor area against your FAR.