Seascape, Auckland, New Zealand

Opportunity

Changing the face of Auckland’s skyline, Seascape will set standards for apartment living. Our client wanted to create a building that would meet high expectations of luxury living and would be seen by Aucklanders as enhancing the city’s skyline and prestige. The elegant tower will comprise of apartments, a health club, retail and office space, and car parking.

One of the fundamental requirements of the project is for every apartment to have a clear view of one of the city’s most iconic features – the Waitemata Harbour.

Solution

Our role covers all aspects of structural, mechanical, electrical, hydraulics and façade engineering. We have established a team of sub-consultants to provide expertise in fire engineering and protection, geotechnical, civil, traffic, surveying, wind, damping and acoustics. Our integrated solution enabled us to optimise the entire building design – and the result is a building where all components work harmoniously together to perform efficiently.

One of the most challenging aspects of the design was to achieve unobstructed views to the north from every apartment. This influenced all elements of the design. Together with the architects, we designed a structure that had no stability elements on the north elevation. Instead, a mega-frame on the east, west and south elevations provides the building’s solidity.

To meet shading requirements and respect the neighbouring streets and landscape, the design tapers to the apex in a unique asymmetric, chisel-like shape. The mega-frame and chisel shape form the building’s aesthetic appeal: the structural steel mega-frame is braced in a diamond pattern and provides a striking form, while the chisel shape displays and impressive and unique shape on Auckland’s skyline.

The height and slenderness of the tower presented another challenge: controlling building sway caused by wind and other lateral forces. Typically, tall buildings have a device known as a tuned mass damper to counteract sway. But these can be large and occupy premium floor space at the top of buildings, which in this case would equate to a NZD$5M loss in revenue. We developed an innovative alternative – a bespoke distributed viscous damping system. As well as controlling oscillation, our solution results in no loss in floor area, and because it uses widely available technology, is cost effective.

Our tall building specialists around the globe collaborated to identify and mitigate potential risks. They identified a problem with the procurement of pre-cast products, which were costly and would take up to 18 months to be delivered. We engaged the contractor early and altered the floor system to a lightweight composite slab on metal decking system. The risk of using pre-cast products was eliminated, and the cost controlled.

Outcome

At a height of 187m, Seascape will be the tallest residential tower in New Zealand. All 221 apartments are north-facing and provide unencumbered views of Waitemata Harbour.

At the base there will be four floors of retail and restaurants with pedestrianised, public lanes providing access to the surrounding area.