What's the Difference Between Rentable and Usable SF?

Usable square footage refers to the actual space a tenant can occupy and use within their suite or office, excluding common areas like lobbies, hallways, and restrooms. Rentable square footage includes both the usable space and a proportionate share of the building’s common areas, meaning tenants pay rent on more space than they physically use. The difference between the two is captured by the load factor, which helps landlords allocate costs of shared spaces among tenants.

Definitions

Term Definition
Usable Sq Ft The square footage a tenant can actually occupy and use for their business.
Rentable Sq Ft Usable square footage plus a share of common building areas.
Load Factor The ratio that explains how much common space is added to usable space to calculate rentable space. Formula: Load Factor = Rentable Sq Ft / Usable Sq Ft

Load Factor = Rentable Sq Ft / Usable Sq Ft

Example

Component Square Footage
Usable Space 5,000 sq ft
Building Common Areas 2,000 sq ft
Total Rentable Space 6,000 sq ft
Load Factor 1.20 (6,000 ÷ 5,000)

In this case, the tenant occupies 5,000 sq ft but pays rent on 6,000 sq ft due to the building’s 1.20 load factor.