We have a corridor separating a north and south tenant space. The corridor leads to a lobby at one end and an exit stair at the other end. In the future, it is possible this corridor could be removed and one tenant takes the entire space. So would you classify this corridor as Floor Service Area rather than Building Service Area? I would consider it as FSA because its inclusion (or exclusion) has no impact on other storeys. That being said, I've also seen mention that egress corridors could be BSA.

Any clarification or rule of thumb is appreciated. Thanks