Glossary

Core Factor

Also known as: floor common area factor

The portion of a floor's load factor attributable solely to that floor's own common areas — elevator lobby, restrooms, electrical and telecom closets, stairwells — as distinct from building-wide common areas captured in the add-on factor.

Core factor isolates floor-specific inefficiency from building-wide inefficiency, which matters because the two behave very differently across a building's floor plate. A floor with a single, tight central core (elevators, restrooms, and risers clustered efficiently) will have a low core factor regardless of what happens elsewhere in the building, while a floor with a sprawling or duplicated core — common on lower floors that also serve as a lobby overflow or on floors with redundant stairwells for code compliance — will carry a materially higher core factor than the floors above it. This is why load factors are not uniform throughout a tower: ground and mechanical-adjacent floors often show noticeably higher core factors than typical office floors, a fact that matters when a tenant is comparing floor-specific quotes within the same building rather than assuming a single building-wide efficiency ratio applies everywhere.