This research investigates a new structural system based on a central core of CLT (cross-laminated timber) panels to provide more useful multi-level timber buildings that are taller and with open floor areas. Because pinus radiata is a suitable timber for the manufacture of CLT panels, the system has the potential to add value to planted NZ forests and to earn overseas currency. Timber elements are proposed for the entire building structure – central core, columns, floor beams and floor joists. The vertical timber core is a very large square (or rectangular) hollow section that extends the full height of the building and is the main element for resisting lateral forces. Various aspects of the system are discussed in the paper. An analysis of the structure is reported and the paper concludes that the proposed structural system with CLT elements is suitable for buildings to at least twenty levels.