Glimpsed from the outside, One Shelley Street in Sydney is undeniably a striking building, with huge steel strips wrapped around glass across its two mid-sized towers of seven and 10 storeys. Yet in a building predicated on innovation and on sustainable design principles, this impressive visage only hints at the departure from design convention within.
Designed by lead architect Fitzpatrick and Partners, One Shelley Street set out to be among the largest projects of its kind to achieve a 6 star Green Star rating for Office Design and As-Built, indicating “world leadership” status. It is the national headquarters for Macquarie Bank.
The building is a pioneer in another way, too: It was the first in the country to be designed for activity-based working (ABW).
The two towers are bridged by an atrium. A diagonal grid of 3,000 tonnes of steel not only holds the structure and glass façade together, but delivers an open floor space of 33,000m2 free of supporting columns.
Nothing about One Shelley Street is simple.
Macquarie wanted a headquarters that provided ultimate flexibility, and a team of renowned interior architects and technology consultants was bought in to provide something hitherto unimagined. The end result is a dramatic departure from a traditional office.
The design includes glass-walled meeting rooms that appear suspended within the atrium space across nine levels. Apparently taking inspiration from the nearby docks, the original idea was that these be mechanically “called up” as needed.
In a style that has since become more common as ABW has gained in popularity, each floor was designed to break away from traditional designated offices. Rather, a range of different spaces were designed to allow employees to work from laptops wherever they felt most comfortable on any given day.
These include open social areas, couches, coffee-shop-style booths, communal tables and carrels.
WSP Lincolne Scott (now WSP) was responsible for the mechanical services design.
The unusual fit-out meant the HVAC design had to be flexible and respond efficiently to varying loading. The HVAC solution selected was passive chilled beams connected to a harbour heat-rejection system.
Like other buildings using the Sydney Harbour’s geothermal properties, including the Sydney Opera House, One Shelley Street’s is an open system that draws harbour water through a heat exchanger before being returned to the harbour via a discharge nozzle.
Reducing potable water consumption was the key driver behind the implementation of this system. The designers also aimed to increase energy savings by taking advantage of reducing average condensing temperatures.
WSP Lincolne Scott director John Osborne says passive chilled beams were chosen for several reasons, including that they maximised the net lettable area by allowing the development of an additional floorplate within the building’s established height limit.
“The passive chilled beams … provided significant IEQ benefits to the tenant over other systems, are energy-efficient, and their passive design aligned itself with the project’s ESD aspirations,” he says.
The building’s heating is supplied via the primary air-supply system, which has two roles: dehumidification and heating. Heat is also reclaimed from the condenser water to assist in heating.
Only the third NSW building at the time to earn a 6 star Green Star As-Built rating, One Shelley Street’s designers achieved this without onsite energy generation – an uncommon feat.
Osborne says for the building to earn its 6 star Green Star ratings without these “bolt-ons” is testimony to its design and the commitment shown by all stakeholders.