Key takeaways
- FAR is the total covered area of all floors divided by the plot area.
- Height limits, setbacks and parking rules can stop a design before FAR does.
- Always check the current bylaws for your exact plot before buying or designing.
Floor area ratio (FAR) is the total covered area of all floors of a building divided by the area of its plot. A FAR of 1:4 means the floors added together may cover four times the plot area. It is the first number to check when you assess what a commercial plot can become.
A simple example
Take a 1,000 sq yd plot with an illustrative FAR of 1:4. The permitted covered area is 4,000 sq yd. Built on half of the plot, that becomes about eight floors; built on the whole plot, about four. The figures here are only an example; the actual FAR depends on the plot's zoning.
| Plot area | FAR | Permitted covered area |
|---|---|---|
| 1,000 sq yd | 1:4 | 4,000 sq yd |
| 1,000 sq yd | 1:6 | 6,000 sq yd |
| 1,000 sq yd | 1:8 | 8,000 sq yd |
What else limits the design
- Height limits for the area and for airport safety
- Setbacks from the plot boundary and the road
- Parking requirements, often met with basements
- Ground coverage limits on how much of the plot the building may occupy
- Fire safety rules for escape stairs and access
A feasibility study tests FAR, height, parking and cost together. See our real estate development service or send us your plot details.