(pronounced bays BIHL-ding)
An interior designer works within and draws up plans for an area with the confines of an overall building shell, and that structure is typically called the base building. Before an interior designer begins a project, he or she will (hopefully) receive a set of base building drawings, which show the existence and location of exterior walls and glazing, interior core and demising walls, as well as existing floors, ceilings, and lighting, and systems (mechanical, electrical, plumbing, etc.) in place to operate the building. These items typically cannot be altered in any way, and the designer must work within the confines of the base building.