The primary structural floors are at every second level and are composite floor slabs spanning 4.3 or 5.3 metres. In an effort to reduce the weight of the concrete, even the slab depths were varied from 110 to 150mm according to span. The building is fire protected by a combination of fire sprayed material and fire rated plasterboard, a solution derived using the deemed to satisfy (DTS) provisions of the Building Code of Australia (BCA). The perimeter columns and beams have been fire sprayed and the building, both old and new sections, is fully sprinklered. Extracted from steel Australia Sep 05.