Core, partition and exterior walls
Every wall on a floor plate is doing one of three jobs. The exterior wall is the envelope, holding the building’s outline and its glazing. The core wall encloses the lifts, stairs and services. A partition divides the space left over.
On a drawing the distinction is usually carried by line weight and hatching rather than by any label. A heavy line reads as envelope or core, a light one as partition, and the convention is consistent enough within a single drawing set to be reliable. Across sets from different offices it holds only loosely.
Why the roles matter
They separate the permanent from the temporary. Envelope and core are the floor as it will be in ten years. Partitions belong to whoever occupied the space last, and they are the first thing a strip-out removes.
So a tenant looking at a plan is really asking which lines survive their fit-out. A floor that looks cellular can be an open plate with a departed tenant’s partitions still drawn on it. Reading the roles is what tells the two situations apart, and getting it wrong costs an inspection at best.
How StudiO resolves them
Wall roles are decided per segment rather than per wall. A single line on a drawing can run from the envelope, past a core, and continue as a partition, so each segment is measured for thickness and typed on its own evidence. The result carries into the model and the fitted plan, where the envelope, the core and the partitions are drawn differently and can be inspected.
One limit, plainly. These roles describe what a wall does on the plate, not whether it is load-bearing. That question belongs to the structural drawings and to the engineer who stamped them.