Written by Alan Johnson for TecTorque Autumn 2015.
When complete, Barangaroo will showcase how city populations can live sustainably.
Being Australia’s first carbon neutral building means neutral in operation, inclusive of electricity and gas use, residual waste emissions, and commuters travelling to and from the site. The precinct’s sustainability initiatives include an on-site blackwater treatment plant capable of supplying one million litres of recycled water a day to the precinct and surrounding buildings.
The recycled treatment plant will be able to produce around one megalitre of recycled water a day, which will be distributed to all the buildings for flushing toilets, washing down and irrigation.
When the first of the Barangaroo buildings (Tower 2) opens later this year, Sydney-siders and visitors alike will be amazed by the building’s beauty and fine architectural lines overlooking the harbour, but what most people won’t realise is that the majority of the innovative elements of the building are hidden away. Currently under construction on Sydney’s CBD harbourside, the 42-storey Tower 2 is the largest building to receive the 6 Star Green Star - Office Design v3 rating, and is shaping up to be in Sydney’s most vibrant precinct, all in Australia’s first carbon-neutral community.
Sydneys Biggest Development since 2000 Olympics
Valued at over $6bn, Barangaroo is Sydney’s biggest development project since the 2000 Olympics and one of the most significant waterfront regenerations currently underway anywhere in the world. When complete, Barangaroo will showcase how city populations can live sustainably, all serviced by new and extended transport systems. Over time, 23,000 people will live and work in the precinct, with 33,000 people expected to visit Barangaroo each day. It will be progressively delivered over the next ten to fifteen years.
The 22 hectare site has been divided into three redevelopment areas - Barangaroo Point with six hectares of public waterfront walks and parks, Barangaroo South a major new business, tourism, residential and retail precinct, while Central Barangaroo will be a cultural and civic focal point for recreation, events and entertainment. At this stage, Crown’s much talked about hotel and casino is still not finalised, with Crown expected to submit a Development Application to the NSW Government showing the plans and design of the hotel in the near future.
Owned by the NSW Government and managed by the Barangaroo Delivery Authority, Lend Lease was granted the development rights for the Barangaroo South precinct. Anita Mitchell, Lend Lease’s General Manager Sustainability at Barangaroo South, describes the project, which has Tower 2 as the central of the three buildings comprising International Towers Sydney (ITS), as a once in a generation opportunity to reshape the city of Sydney. We are building something really special here. These buildings will be world class in terms of their energy and water performance, and their waste management. “They will stand here for the next 50 to 100 years, for we have built and hard wired the infrastructure to stand the test of time.”
Mitchell explained that all three ITS buildings will feature high-performance solar shading facades as well as energy-saving centralised cooling systems that utilise water from Sydney Harbour. The buildings will be part of a precinct-wide sustainability strategy which assists not only the commercial and residential buildings at Barangaroo South but also the local neighbourhood.
“Plus with energy-efficient designs, on and offsite low carbon and renewable energy teamed with zero carbon waste treatment and commuter carbon emission offsets, it will result in a net carbon neutral outcome for the precinct’s operational energy use,” Mitchell said. The precinct’s sustainability initiatives include an on-site blackwater treatment plant capable of supplying one million litres of recycled water a day to the precinct and surrounding buildings.
Green Star Rating
Green Building Council of Australia (GBCA) Chief Executive Officer Romilly Madew said a Green Star Design rating requires “a commitment to innovation and a holistic approach to green building design. Once again, Lend Lease has sent a clear signal that a green building can be good for both the environment and the tenants who choose such offices. Those organisations moving into Tower 2 will be working in one of the world’s most sustainable business addresses,” Madew said.
Mitchell explained that the 6 Star Green Star rating for Tower 2 was just the beginning. “Tower 2 was our first cab off the rank, and we have just finalised our round two submission for Tower 3 which is the next building going up.” Mitchell pointed out that Tower 1 has already received enough Green Star points, 78 points under round one, to qualify for a 6 Star rating. (75 points are needed to achieve a 6 Star rating). “T2 is only the second building ever to have enough points after just the first round to achieve a 6 Star rating,” she said. “However, we will re submit it for round two so we can get the additional points, which will take us up to 85 points, then we will announce the rating. “And once we get feedback on the Tower 1 building, we will re-submit our documentation to achieve a 6 Star Green Star rating there as well,” Mitchell said.
Mitchell explains that being Australia’s first carbon neutral building means neutral in operation, inclusive of electricity and gas use, any residual waste emissions, and commuters travelling to and from the construction site. For example, we have carbon offsets for the commuters coming and going, with the precinct fed with renewable energy.
“Plus we have reduced our carbon footprint as much as we can through precinct infrastructure and building design, and the amount of electricity used within the precinct. For the rest of the electricity demand we have installed just over 6000m2 of solar panels, which covers nearly all of the buildings’ roof tops. We also will have about a megawatt of gas fired generation, which is still to be finalised, but it will be put in as another demand site initiative, and then we move to an off-site solution.”
Carbon Neutral in perpetuity
Lend Lease has established, through its 99-year ground leases and tenancy agreements, that owners and tenants contribute to the support of the community carbon fund, meaning the Barangaroo precinct is carbon-neutral in perpetuity.
“What’s different about this site is that we have included other emissions such as tenancy emissions to become a carbon-neutral precinct.” Mitchell explained that the Barangaroo project is one of 18 projects globally that are part of the US Clinton Climate Initiative’s Climate Positive Development Program designed to tackle climate change.
“The Victoria Harbour project, which is another Lend Lease project, is the only other one in Australia, with the other projects scattered around the world.”The projects are looking at different ways of achieving carbon neutrality in practice.
“As part of the program, with the help of the City of Sydney, we share the mechanisms we are using, which can then be picked up and used around the world to tackle climate change. “And Barangaroo is the first project to have its roadmap certified. We are really leading the way in how a big urban development project can actually provide for a new city, but do it in a way that does not impact on the environment,” she said.
While Tower 2 is on track to open as scheduled in the middle of this year, Mitchell admitted the project has not been without its challenges. “Where we are building has been one of the biggest challenges; building on reclaimed land. “Getting the project out of the ground and the remediation of the contaminated land was very challenging. It took a lot of time and effort at the beginning of the project.” Then having the harbour right next to project was another major challenge for the construction company. To keep the water out, the company built a massive retention wall system, much like a giant bath tub, to keep the harbour out. “Once we had that in place we could focus on more traditional methods of construction, putting in piles and slowly getting the building out of the ground,” Mitchell explained.
Another of the challenges the company faced was the implementation of the shared infrastructure, in both a legal and practical sense, adding a lot of complexity to the project.< “Getting building owners to understand that they won’t be owning their chiller, for example, was one major challenge. “Then we had to work out how to allocate energy to different buildings, things like materials credits and how to rate a building that ties into an existing building that might have been rated under a different version of the Green Star rating system five years ago.”
Mitchell admitted it was very difficult at times working through all the issues involved with a shared infrastructure. “However, the GBCA and our neighbours have been incredibly supportive in helping us overcome these logistical issues of trying to rate stand-alone buildings with shared infrastructure.
“People have talked about precinct shared infrastructure as the way of the future, but we are the first company to do it in Australia, and have had to change the rules as we have gone along,” she said. There are many examples of shared infrastructure in Europe and the Middle East but this is the first time in Australia in a precinct nature.
Interestingly, Lend Lease has built the infrastructure and, at this stage, is planning to have private utility ownership of that, rather than as a government utility. The utility will distribute chilled water for air conditioning, and recycled water to the buildings in the precinct, to flush the toilets, cleaning and irrigation. Plus the precinct has its own electrical network, which is connected to the Ausgrid network with a higher voltage, 33kv, than the traditional voltage found in Sydney’s CBD.
Mitchell is unsure whether the shared infrastructure concept will take off in Australia. “We had a unique opportunity here, to build our own little city. Whether there are similar opportunities in other large CBD developments, to bring in private utilities to service buildings like they have in Paris, Barcelona and Dubai, remains to be seen. “Having a shared infrastructure introduces a whole range of efficiencies that you would not get by doing one building at a time.”But she readily admits it would be very difficult to do something like the Barangaroo project retrospectively.
“And because we have a huge mixture of residential, commercial and retail, we have a wonderful diversity across the buildings, and when occupied, will operate at different times of the day. “This mixture has allowed us to minimise the capacity we have had to put in, which has helped us with our efficiencies in water consumption and electricity usage,” Mitchell said.
While building a 6 Star Green Star building comes with additional costs, Mitchell says Lend Lease was able to reduce the cost impact considerably by being innovative and efficient in the construction process. “By having centralised services that frees up a lot of premium space in the buildings that would traditionally be used to house all the building’s infrastructure plant. “Plus we are able to pull out around 10 per cent of the total infrastructure costs because of the centralised services, and the diversity of load. “Obviously there is some degree of premium to build a 6 Star building, but the tenants we are working with demand that environmental level of construction,” she said.
Mitchell pointed out that the precinct is packed with innovative ideas gleaned from around the world, all designed to make the buildings more efficient and environmentally friendly.The design of the energy saving centralised cooling system, for example, does not use cooling towers to reduce the buildings’ heat, instead Lend Lease is taking advantage of the location, and will take water out of the harbour.
The water will go through a cooling plant in the basement of the building, and take all the heat away from the building and transfer it into the harbour. Mitchell says the heat dissipates very quickly and will have no negative impact on the marine life in the harbour environment. Interestingly, there are a few other buildings around Sydney harbour which use water from the harbour for cooling purposes, including the Opera House and the AMP building since the late 60s. However, the Barangaroo project is by far the largest one.
The environmental team have done an enormous amount of thermal modelling to understand the potential impact on the harbour, from an ecological point of view, plus take into consideration all the other buildings around the harbour. “The EPA has seen all our modelling and the organisation is quite happy with what we will be able to achieve,” she said.
Mitchell estimates they will probably end up with 16 large chilling machines in the basement, which will be capable of delivering up to 72 megawatts of refrigeration, making it the biggest plant in Australia. As well, they have developed non-toxic systems that will prevent marine growth in the cooling system and overcome many on-going maintenance issues. Mitchell pointed out that the recycled treatment plant is water positive. “Meaning we will export as much recycled water off site as the amount of potable water we use on site.”
In its development capacity, the plant will be able to produce around one megalitre of recycled water a day, which will be distributed to all the buildings for flushing toilets, washing down and irrigation. “We also have the potential to export the water to other buildings including Barangaroo Central and Barangaroo Park,” Mitchell said.
RecyclingAnd not just recycled water, 99% of the construction waste on site is presently being recycled. “We had a target of 97% but we are currently achieving 99% of construction waste. A great achievement,” said Mitchell.
To reduce the need for air conditioning, the environmental team has developed an innovative solar shading system. “We have modelled every façade on the Tower 2 building. Working with the architectural team, we have come up with both fixed and moveable shading elements. The moveable elements are the internal blinds, while the fixed shades are both vertical and horizontal to maximise daylight.” Mitchell said they decided against floor to ceiling glass. “It looks prettier, but adds a lot of heat loads. Instead we opted for windows with a small spandrel to add to the thermal efficiency of the building.”
Less Embodied Carbon
Another major environmental innovation Mitchell is particularly proud of is achieving 20% less embodied carbon in the buildings compared to standard construction practices. “It’s great to be carbon neutral in operation, but there is an enormous amount of carbon that is embodied into a building. The concrete, the steel, the glass and the aluminium, for example, all have a fairly heavy carbon footprint.
“We have had an analyst working with us for over four years looking at ways of taking carbon out of our supply chain, plus working with our design team to minimise our carbon footprint by ‘dematerialisation’. “By that I mean areas such as rationalising the number of piles, looking at the floor to slab thickness to make sure we have not over engineered any of the structures. That’s been an enormous project that we have undertaken.”
The team has also worked with Boral, the project’s concrete supplier, on producing different concrete mixes, with low-carbon Portland cement replacement products used where the team can. Boral has two concrete batching plants on site, which supplies most of the concrete on site giving the team complete control of the quality and timings. “We have also worked with our façade contractors and steel manufacturers to go back through their supply chains to maximise the use of the most low-carbon embodied products possible,” Mitchell said.
As well as the environmental sustainability, equally important to Mitchell is the social sustainability side of the project, with a heavy engagement with the Indigenous community, with a community Indigenous hub onsite, for example. “We are targeting 500 Indigenous workers being engaged as workers onsite throughout the life of the development, and work closely with Supply Nation, for example, for various sub-contractors and materials we can use onsite.
“For the skilled trades, 20% of the skilled trade work on site is targeted to be done by apprentices to boost apprenticeship numbers. “Plus we have established the Barangaroo Skills Exchange, which is basically an onsite TAFE funded by Federal Government through the Skills Connect program, to subsidise the training onsite.”
Mitchell said they have had more than 10,000 accredited learning outcomes already, and a very big uptake from the workforce to upgrade their technical skills as well as their language and numeracy skills. “Many of the workers were surprised to see it here, but they have really embraced it as their own.”At present there are just over 2000 workers on site, but that figure is expected to grow over the coming months as the Tower 2 building moves into finishing trades with an increase in manual labour.
Mitchell is rightly very proud of what they have delivered to date, an extension of the CBD right down to the waterfront. “This is my dream job, and we are on track to achieve our ambitious goal of making Barangaroo the new benchmark in terms of its economic, social and environmental outcomes,” Mitchell concluded.