Outdoor balconies on the 67th floor, placement of a new residential tower on top of an existing commercial building and special artworks are part of architectural and engineering features that define the tallest residential tower in Sydney which has just opened.

Issuing a joint statement, principal architects BVN and Woods Bagot along with principal engineer Arup have announced that the 67-storey Greenland Tower located at 115 Bathurst Street in Sydney has been completed and is now open.

Now Sydney’s tallest residential tower, the building rises to 235 meters and includes 479 apartment residences.

It features a council administered creative hub, retail spaces and a new public realm network associated with the heritage-listed Water Board building (which is undergoing refurbishment to become a boutique hotel).

From an architectural and engineering viewpoint, several features of the new tower stand out.

First, there is the placement of outdoor balconies/verandas even on the highest levels.

Known as the ‘Sydney balconies’ or ‘Sydnye verandas’, these will enable residents to embrace the open air and enjoy spectacular outdoor views of the CBD, Blue Mountains, Hyde Park and Sydney Harbour.

Normally, outdoor balconies are not common on buildings of greater than 20 storeys amid concerns about wind load and lateral force.

On Greenland, however, the Sydney Verandas feature vast angled panes of glass which are suspended from hand-like clips. These deliver protection from large wind forces whilst also enabling fresh air, gentle breezes and light rain to enter into the space.

When sitting outside, the balconies will enable residents to enjoy aforementioned views along with timber decking, hot summers, cicadas and slow afternoons.

Such are the size of these that designers say they will enable ‘the return of cocktail hour’.

Next, there is the building’s structure itself.

This involves the placement of a new 41-storey building on top of an existing 26-stoery one.

When constructing new residential towers, a common approach is to demolish any existing buildings and create a new structure from scratch.

With Greenview, however, the new 41-storey residential tower was constructed on top of the existing commercial building which was originally built in the 1960s.

Adding to the challenge was that the existing building was constructed right up to the edge of the western boundary. For this project, the new building sitting on top of the existing one needed to be set back.

To make the additional height possible, the design team stripped the concrete from the original steel structure and reinforced the foundation.

To overcome the boundary issue, meanwhile, a new angled truss erected on top of the original building. This was strong enough to hold a new cantilevered 40-storey tower.

With this solution came the opportunity for 360-degree light and views.

As a result, the building strikes an unusual pose in the CBD with its unique shifting silhouette and dappled mosaic of windows reflecting and capturing the shifting light.

Next, the ground floor carpark has been ‘hidden’ inside the building. This happens as the car park is surrounded by rehearsal and production spaces which are associated with the creative hub referred to above and which wrap around the carpark.

Finally, finishing touches involve unique artworks.

Designed by US artist Larry Bell, for example, red angles which frame the entry from Bathurst Street resemble the triangles that define the building from the folded framing of the Creative Hub to the angular shapes of the Sydney Verandas.

Meanwhile, artworks from local artist Agatha Goeth-Snape involve constating curbs which will welcome people inside the residential lobby and create movement.

Designed by US artist Larry Bell, for example, red angles which frame the entry from Bathurst Street resemble the triangles that define the building from the folded framing of the Creative Hub to the angular shapes of the Sydney Verandas. (iimage: provided)

In their statement, above firms say the new tower is an extraordinary architectural and engineering feat.

“It’s taken many minds to forge such an elegant solution to an initially confounding challenge,” the firms said.

“And the outcome is a shared success for Sydney.”