This existing 20 level building constructed in 1968 was gutted back to its concrete structure and redeveloped along with the construction of a new seismically isolated 9 level building next door. The end result was over 25,000 m2 (270,000 sqft) of commercial office, retail and carparking.
As the office levels, 22,000 m2 (240,000 sqft) on levels 1-19 were occupied by a single Government tenant there was a need to incorporate a new internal circulation stairs that linked levels 3-18. The stairs were able to be open across a total of 11 of those levels without the use of mechanical smoke control systems.
The constraints for the existing structure meant a focus of the fire engineering design was to be able to utilise the existing stairs that did not comply in geometry to current Code. Holmes Fire had previously carried out a fully filmed and documented egress study for the building (as part of an employee’s PhD study) which was able to be used to understand how the occupants (over 2000 of them) used the existing stairs under evacuation conditions. This deep knowledge of the building was crucial in developing a solution that satisfied building officials and the Government tenant.
The age of the building meant that at the outset the building sat outside the new-Code standard and on that basis the redevelopment was able to deliver a modern and new-Code-compliant building with substantial fire safety upgrades. Which is a significant and effectively ‘new’ for the building owner.