A demising wall is a partition that separates one tenant space from another, typically used in buildings with multiple tenants like office buildings, apartment buildings, retail strip malls, or commercial buildings. These walls can extend from the concrete floor to the underside of the tenant structure or roof deck and may run horizontally to exterior walls or other rated partitions. Demising walls are also known as separation walls, fire walls, party walls, divider walls, common walls, or occupancy separation walls.