There’s been huge collaboration between, architects, engineers and council with a strong eye to social as well as environmental sustainability, in one of Sydney’s new skyscrapers.
3XN doesn’t just design buildings. It designs social structures that help foster cultural, corporate, and even national cultures, according to Fred Holt.
The architect and partner in charge at the renowned Danish architectural firm says design should be about much more than what a building looks like and how it performs. It should be about how people interact with each other and the space inside and around a building.
“We feel that our work is not just about creating a useful environment; it is about people and space, their interaction, and that is really important from a socially sustainable point of view,” Holt told the audience at the recent Tomorrowland19 conference in Sydney.
Holt’s presentation opened a window on the thinking that is helping build what could end up being one of Australia’s most radical and sustainable skyscrapers.
The tallest building in Sydney when it was completed in 1976, the AMP Centre is undergoing a major revamp that 3XN says will make the building feel more like a “vertical village” than a 200-metre high-rise office block.
Five years in the planning, Quay Quarter Tower (QQT), as it is now called, forms part of a new 11,000 square-metre mixed-use precinct at Circular Quay, which includes urban green space and about 5000 square metres of services, food and retail outlets.
Construction on the tower started last year and is expected to finish in late 2021. It is targeting 6-star Green Star and 5.5 star NABERS ratings.
3XN has master-planned the renovation of the old building, owned by AMP Capital, and is working with Australia’s BVN as the local architect, while Tom Dixon’s internationally-renowned, London-based design firm Design Research Studio, which will design the lobby and connected facilities in the towel.
Multiplex is the construction partner, while Sydney building services company Arup has been working with AMP Capital since the project’s beginning. It undertook a feasibility study for the new precinct, and has devised engineering solutions for various aspects of the tower and precinct.
Sustainability at the heart of the design
AMP will take up an anchor tenancy of 36,500 square metres in the building, while Deloitte Australia has committed to a 10-year lease over about 32,000 square metres, bringing the total pre-commitment of QQT, at the time of writing, to 76 per cent.
With 90,000 square metres of premium-grade office space, QQT is being hailed as a benchmark development in the Sydney CBD.
Sustainability – both social and material – is at the heart of the design, which incorporates two thirds of the old building into the new structure. Arup estimates that reusing all that embodied energy will save the equivalent of the CO2 that would be generated by 10,000 plane flights from Sydney to Melbourne.
The existing tower sits tightly between other large buildings at Circular Quay, leaving little wriggle room for the new design.
So, in a bid to increase the floor plate by a third, maximise city and harbour views, and control the amount of direct sunlight hitting the building – and hence, the energy needed to cool it – 3XN devised an unusual solution that involved “stacking” the glass volumes at different angles.
The stacks will help shade the tower’s northern façade, cutting the need for electrically-powered blinds.
Rotating the tower this way will also create a series of external terraces with shared amenity spaces for tenants, which will direct daylight deep into work spaces.
As Arup explains it, the shading “folds and tapers, following the sun as it moves from east to west, minimising glare, providing thermal comfort and preserving those all-important 360-degree magnificent views of Sydney”.
Principal at Arup, Robert Saidman, says the team had “great fun” fine-tuning the exact shape and profile of the shading.
Constraints can drive design
“It will drive the façading industry in terms of glazing technologies further,” he told Tomorrowland19. “We look forward to the day where the idea of shade is not a bad thing, particularly in the city.”
Saidman says the challenges posed by the project could only be overcome by closely studying the structure of the existing building and the way it interacted with the site.
“There are lots of challenges but I think the key thing is that regardless of the building … you can only do [something like the stacks] by really understanding the bones of the building, understanding the constraints of the building, understanding how can you weave a new design into an existing structure … but the outcomes can be fantastic.
“One of the big initiatives, that was particularly challenging [to achieve] … is that we will be moving literally double the amount of people through the new building but we have only increased the core by 30 per cent,” he says.
“We have done that via a double deck lift, the first in an existing building in the world, that I am aware of.”
The lift – two cabs on top of each other that allow passengers on consecutive floors to use the lift at the same time – save space at the core of the building, adding 45,000-square-metres to the old floor plate.
“We need more exemplars like this that show the possibility and equally value the embedded carbon that has been retained,” says Saidman.
Eve Clark, design director of AMP Capital Investors, told the annual international conference of the Council on Tall Buildings and Urban Habitat, earlier this year that QQT was a building of “so many firsts”.
“It’s certainly the first building, too, to be offering so much totally connected amenity on the ground plane, and the first to have so much open atrium area,” Clark says.
Can QQT’s re-use of an old core for a new building be replicated?
You can’t just chop off parts of buildings and extend them, but there are opportunities elsewhere, Holt says.
“The advantage [we have] is that we are on an island site with a lot space to the north but not all buildings have that.”
Western Sydney University professor of practice for architecture, Peter Poulet, agrees.
QQT is a design that suits a unique site and a particular existing building, he says, noting that the architects and engineers were “seamless in their approach”.
“It points to the integrated thinking that is required to achieve this.”