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Floor Area Ratio Calculator

Floor Area Ratio Formula

sq. ft.

1. What is Floor Area Ratio Calculator?

Definition: This calculator computes the maximum floor area allowed for a building based on the lot size and the allowed Floor Area Ratio (FAR).

Purpose: Assists urban planners, architects, and developers in ensuring compliance with zoning regulations and optimizing building design.

2. How Does the Calculator Work?

The calculator uses the formula:

Floor Area Ratio Formula:

\( \text{Maximum Building Size} = \text{FAR Limit} \times \text{Lot Size} \)
Where:
  • \( \text{FAR Limit} \): Allowed Floor Area Ratio (no units)
  • \( \text{Lot Size} \): Lot size in square feet (sq. ft.) or square meters (sq. m.), converted to sq. ft.

Steps:

  • Enter the lot size with unit (sq. ft. or sq. m.) and the FAR limit.
  • Convert lot size to square feet if in square meters (1 sq. m. = 10.7639 sq. ft.).
  • Multiply by the FAR limit to calculate the maximum building size.
  • Display the result with 2 decimal places.

3. Importance of Floor Area Ratio

Calculating the floor area ratio is crucial for:

  • Zoning Compliance: Ensures buildings adhere to local planning regulations.
  • Space Optimization: Helps maximize usable floor space within legal limits.
  • Urban Development: Balances density and open space in city planning.

4. Using the Calculator

Example 1: Lot Size = 20,000 sq. ft., FAR Limit = 1.0:

  • Lot Size: 20,000 sq. ft.
  • FAR Limit: 1.0
  • Maximum Building Size: \( 1.0 \times 20,000 = 20,000.00 \) sq. ft.
  • Result: \( 20,000.00 \) sq. ft.

Example 2: Lot Size = 1,858 sq. m., FAR Limit = 0.5:

  • Lot Size: 1,858 sq. m. (≈ 20,000 sq. ft.)
  • FAR Limit: 0.5
  • Maximum Building Size: \( 0.5 \times 20,000 = 10,000.00 \) sq. ft.
  • Result: \( 10,000.00 \) sq. ft.

Example 3: Lot Size = 2,000 sq. m., FAR Limit = 1.5:

  • Lot Size: 2,000 sq. m. (≈ 21,527.80 sq. ft.)
  • FAR Limit: 1.5
  • Maximum Building Size: \( 1.5 \times 21,527.80 \approx 32,291.70 \) sq. ft.
  • Result: \( 32,291.70 \) sq. ft.

5. Frequently Asked Questions (FAQ)

Q: What is a typical FAR limit?
A: Varies by zoning; urban areas may allow 1.0-5.0, suburban areas 0.5-1.5.

Q: Why convert to square feet?
A: FAR regulations in many regions are defined in square feet, requiring consistent units.

Q: Where to find FAR limits?
A: Check local zoning codes or municipal planning departments.

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