Floor Area Ratio (FAR) RechnerFormel

## Floor Area Ratio (FAR)

FAR is a zoning measurement that compares the total floor area of a building to the area of the lot it sits on. It controls building bulk and is especially important in urban zoning.

### Formula

**FAR = Total Building Floor Area / Lot Area**

For example, a 6,000 sq ft building on a 15,000 sq ft lot has a FAR of 0.40.

### How FAR Controls Development

- FAR of 0.25-0.50: Low-density residential (single-family)
- FAR of 0.50-1.0: Medium-density residential (townhomes, duplexes)
- FAR of 1.0-3.0: Mixed-use, multifamily, low-rise commercial
- FAR of 3.0-10.0: Urban commercial, mid-rise to high-rise
- FAR of 10.0+: Dense urban core (Manhattan-type development)

### FAR vs. Lot Coverage

- Lot coverage limits the footprint; FAR limits total floor area
- A tall, narrow building can have a high FAR with low lot coverage
- Both must be satisfied for zoning compliance

### FAR Bonuses

Many cities offer FAR bonuses for public plazas, affordable housing, LEED certification, or transit-oriented development.

Lösungsbeispiel

A 15,000 sq ft lot with a 2-story building totaling 6,000 sq ft, and a maximum allowed FAR of 0.50.

  1. Current FAR: 6,000 / 15,000 = 0.40
  2. Maximum allowed floor area: 15,000 x 0.50 = 7,500 sq ft
  3. Remaining buildable: 7,500 - 6,000 = 1,500 sq ft
  4. Average floor plate: 6,000 / 2 = 3,000 sq ft
  5. Implied lot coverage: 3,000 / 15,000 = 20.0%
  6. FAR utilization: 0.40 / 0.50 = 80.0%