Understanding Unit Density in Residential Developments
Unit Density is a measure used to determine the number of allowable dwelling units on a specific parcel of land. This concept applies to multifamily, condominiums, single-family homes, and hotels. Methods for calculating units allowed are based on each city’s preferred approach.
Calculating Units Allowed Based on Land Size
One common method is contingent on land size. The city provides a units-per-acre or units-per-square-foot value. For instance, if a parcel is 10,000 square feet and zoned for 50 units per acre, you divide 10,000 by 43,560 and then multiply by 50 to determine the allowable units.
Units per Site: A Fixed Number of Allowable Units
Another method is based on a fixed number of units per site, regardless of its size. For example, a 5-acre site might allow one unit per site, encouraging the landowner to subdivide the parcel to create more units. This method is common in single-family districts.
Navigating Floor Area Ratio (FAR) to Estimate Allowable Units
In some cities, Unit Density is not explicitly specified. Instead, you must rely on the FAR and the total buildable area to determine allowable units. If the total buildable area is 100,000 square feet, you could factor in a 20% loss factor divided by the desired unit size.