Altair

This 139 unit apartment development is located over the Kings Cross tunnel, bounded on 3 sides by Kings Cross Road, Ward Avenue and Craigend Street. The Western boundary abuts the podium of the Elan apartment building. The site offers dramatic 360 degree views of Sydney, from Sydney Harbour to the north, Botany Bay to the south, the CBD to the west and the eastern suburbs to the east.

Being located over a 4 lane traffic tunnel this building has some unusual constraints in relation to structure and carparking. There is a precast concrete protective deck over the tunnel roof, which 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 approximately 8 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 the 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 2 lift/service cores, containing units which have south/east/west orientation, and have no immediate neighbours due to the separation of the cores.

The apartments have been designed to take full advantage of correct orientation and natural cross ventilation, combined with deep overhanging balconies and external aluminium brises soleil providing sun-shading, so that air conditioning is not required in the building. There is natural gas heating available for winter should it be required.

The structure of the building comprises 200mm thick 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 will appear denser at lower levels due to the larger number of smaller apartments on those levels.

The apartment mix comprises 3 one-bedroom loft apartments in the podium, 44 one-bedroom apartments, 42 one-bedroom + study (home office) apartments, 20 two-bedroom apartments, 20 three-bedroom apartments, 8 three-bedroom sub-penthouses and 2 three-bedroom penthouses. There is a 25m lap pool, children's pool and spa pool as well as a gym and common room on the landscaped roof of the podium. A large cafe and delicatessen are located on the plaza at the eastern end of the site adjacent to the main entry to the building.

Typically the kitchens and bathrooms have been designed as freestanding pods within the apartments allowing breezeways through to the bedrooms on the south side. These pods are clad in coloured polyurethane panels to clearly distinguish them from the white painted load bearing walls. The kitchen island benches are fully clad in stainless steel with a 1200mm high white resin surround on 3 sides screening the bench from living areas.

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 the 3 loft apartments read as deeply recessed slots cut into this perforated base providing additional life at street level, while the cafe is a lightweight steel and glass pavilion to clearly differentiate it from the podium.