An open floor plan is an indoor office or industrial space with a wide span which is uninterrupted by columns. This quality is often coincident with the capacity for variable wall construction, but is not the same thing. Normally variable walls can be built when an open floor plan exists, although it may not be allowed by the owner. An open floor plan implies a structural arrangement of the building's framework so that no columns or load-bearing walls intrude on the floor space, except for a structural core at the center, side, or corner of the plan.

A central, side, or corner core is permitted. The open span otherwise lacks structural columns or load-bearing walls intruding into the floor space.

Variable wall potential concerns flexibility to arrange tenant partitions. An open structural span does not by itself guarantee the owner allows that alteration.