Floor area ratio examples
Divide a project’s total counted floor area by its zoning lot area to find its floor area ratio, also called FAR. Multiply the lot area by the applicable FAR limit to find the area budget for a preliminary study.
Compare floor plates in the parcel study planner →Work through a 10,000-square-foot lot
Suppose the lot is 10,000 square feet and your study uses an FAR limit of 2.0. The area budget is 20,000 square feet. A 17,500-square-foot concept uses an FAR of 1.75 and leaves 2,500 square feet of that budget.
| Concept | Counted floor area | FAR on this lot |
|---|---|---|
| Three equally sized floor plates | 3 × 5,000 = 15,000 sq ft | 1.50 |
| Four equally sized floor plates | 4 × 5,000 = 20,000 sq ft | 2.00 |
| Five equally sized floor plates | 5 × 4,000 = 20,000 sq ft | 2.00 |
Keep existing space in the total
If the concept retains 5,000 square feet of counted floor space on the same lot, subtract it from the area budget before allocating new space. Under the assumed 20,000-square-foot budget, the remaining allowance for the proposed floor plates is 15,000 square feet.
Compare massing choices with the same FAR
The last two rows have the same total floor area. If the floor plates stack vertically, one uses about half the lot at ground level and the other uses about two-fifths. Check the relevant local definitions of lot area and counted floor area, plus lot coverage, setbacks, height, and use limits, before applying these numbers to a parcel.
For illustrated examples of how one FAR can produce several building shapes, see the New York City Department of City Planning’s Zoning Handbook.