ALTAIR Kings Cross, Sydney, Australia | 1998 - 2000

Being located over a 4 lane road tunnel this 139 unit apartment building has some unusual constraints in relation to structure and carparking. A precast concrete protective deck over the tunnel roof forms the lowest carparking level with a further 2 levels of above ground parking forming a 3 storey podium, built to the site boundary on all sides.

Three lines of existing columns at 8.1 metre centres are located on the north, south and centre of the tunnel below, with all building loads having to be transferred onto these columns. A further requirement for safety reasons was that the lift shafts be located over the central wall of the tunnel. As a result the lift cores do not provide any stiffness to the building as would normally be the case, and are in fact hung from the main building structure, which in turn is supported from a 1.5 metre deep concrete transfer structure at the upper level of the podium. The 2 upper level carpark slabs are also hung from the underside of this transfer structure.

The 16 level apartment tower located above the podium has been designed as a narrow rectilinear block running east-west, allowing the majority of apartments to be north facing. There are 2 secondary towers located behind the lift/service cores, containing units which have south/east/west orientation and no immediate neighbours due to the separation of the cores.

The structure of the building comprises concrete shear walls at 8.1 metre centres running in the north-south direction, with a concrete column grid structure on the east and west facades. Within the 8.1 metre grid there is total flexibility to rearrange the apartment mix on any level. With the chosen mix being reflected in the location of the blade walls on the north facade, providing an irregular grid texture which appears denser at lower levels due to the larger number of smaller apartments on those levels

Externally the combination of the deeply recessed balconies, horizontal and vertical brises soleil, crisp white concrete structure and blue-black lift cores provide a highly textured and articulated building, which rests atop a podium clad in precast concrete panels with integral cast ventilation slots for the carparking behind. The main entry lobby and 3 loft apartments read as deeply recessed slots cut into this perforated base providing additional life at street level.

Photographer: Ross Honeysett