Tall Timber Storeys

I face a conundrum. I’ve pulled up on my bike in the pedestrian mall outside Darren’s office, just in time for our meeting at 11am, and this is not the kind of meeting to run late to. But his office is on the 14th floor, and I’m faced with a set of glass revolving doors at the bottom of a tall corporate office tower. There’s no way I’ll be able to take my bike up with me, and neither can I leave it on the busy street loaded with all my possessions.

A couple of apologetic text messages later, Darren comes down to greet me. He takes me to a large underground bicycle compound, called their ‘End of Trip’ facility, to lock up my bike, and then suggests we go for a stroll through the rest of the precinct. He says we’ve still got some time before his team will be ready to give me the tour of the special building I’ve come to see.

Darren is the Development Engagement Manager for the company Lendlease’s new commercial precinct in Sydney’s CBD called Barangaroo South; its three office skyscrapers called International Towers Sydney. He’s warm and friendly, chatting affably while we weave amongst the cafes and apartments of the precinct, with the three towers rising above us.

Construction started here in 2012, and with additional residential towers still to be built, its expected to be completed in 2023. He points out a large neighbouring site covered in rubble, excavators and temporary hangar-like buildings, and explains the remediation work they’ve completed so far.

All this land used to be the site of the Millers Point Gasworks. Decommissioned in the 1920s, they left behind underground tanks containing coal tar and large volumes of contaminated soil, all of which Lendlease is cleaning up before building on it. Transforming it from a contaminated industrial site to a vibrant new commercial precinct, it’s said to be one of the most significant waterfront regenerations in the world.

We return to Darren’s office building, known as ‘Tower 3’, the third of the three towers, and head up to level 14. I’m introduced to Liz, one of the design managers, who will be showing us around, along with two other staff who are joining us: Katherine and Paul. I’ll be entering a construction site, and so I’m given a hard hat, gloves, steel capped boots and safety glasses.

Walking through the precinct, we quickly arrive at the building I’ve come to see: Daramu House, soon to be Australia’s newest engineered tall timber office building.

It stands next to its already completed twin, International House Sydney, the first commercial office building constructed from timber in Australia. Both buildings were developed by Lendlease, which has carried out a number of timber office building projects in Australia, including the ‘25 King’ building in Brisbane.

With Daramu House still under construction, it gives us a chance to see the internal structure of the building, before it becomes hidden by the interior decor of some commercial tenants.

Liz uses her swipe card to let us through the security fence via a turnstile gate, though it doesn’t seem to want to let Katherine pass. After signing us all in at the construction office, she leads us up a flight of temporary stairs to a scaffolded walkway that takes us into the first floor.

Liz starts explaining her work as we walk, though she’s very softly spoken, and I need to lean in to catch what she’s saying. She points out where native timber has been used, such as a massive column made from ironbark holding up the foyer, ironbark columns in the shape of giant ‘Y’s along the ground floor portico, recycled brushbox used for the undercroft cladding, and spotted gum sunshades on the facade.

We reach the interior and enter a world of wood. I’ve been in timber houses before, but nothing of this scale. The walls, floor and ceiling are all a light coloured wood, as well as the support columns along the windows and in the interior. The stairwells and lift shafts are all timber as well. It gives the space a certain warmth and natural feel.

Liz tells us that concrete was used for the ground and first floors, but that there’s no structural steel or concrete from Level 2 up. As we progress up each flight of stairs, the further away from completion each floor is, so it’s as though we’re seeing the layers being stripped away, revealing the basic form beneath.

Liz talks to us about ‘cross-laminated timber’ or ‘CLT’, which is what allows the creation of timber buildings this tall. It was first developed in Switzerland in the 1970s and is sometimes known as ‘jumbo plywood’. Layers of timber are glued together with the direction of the grain perpendicular to the layers adjacent. The improved structural properties allow it to be used in place of concrete panels, while being much lighter, more easily worked and easier to erect than concrete.

CLT performs better under tension, but for the columns, which are under compression, they use ‘glue laminated timber’, or ‘glulam’, which has the layers of timber glued together all oriented the same way. It’s a way of creating larger structural members like beams and columns from smaller sections of wood, and therefore from smaller trees, rather than relying on big timber from old-growth forests.

Popularly referred to as ‘plyscrapers’, these CLT and glulam buildings are apparently growing in number and size. The world’s tallest timber building is Mjøstårnet in Norway, at 85.4m tall with 18 storeys. It took the title from the Brock Commons Tallwood House in Vancouver, a hybrid wood and concrete structure 53m high.

I ask Liz why they do it; why make a timber office building? She explains how the production of concrete and steel, the typical structural elements of modern office buildings, emits large amounts of carbon dioxide. Growing timber, however, actually sequesters carbon. The timber in these buildings is all sourced from sustainable forestry stewardship programs, and all that carbon will be locked away for the life of the building — and even beyond if the wood is salvaged for other building projects.

It also looks good, she says, and having natural features in the working environment is supposed to lead to less stress and greater well-being.

Apparently it’s also easier to build. International House took only 14 months to complete, and Daramu House will likely take only 12. Because it’s such a light building material, it needs far fewer people to put it together, with the elements of the building largely prefabricated off-site.

We continue to explore the different floors, admiring all the wood, and Liz and Paul point out some of the other sustainability features of the building. There’s no cladding over the pipes and conduits in the ceiling, meaning less resources are used and more of the timberwork is on display. A ‘composite material access floor’ creates an interlocking false floor with access to the space below it. It means that cables can be easily laid and altered, so that if there’s a change of tenants and offices need to be re-arranged, less resources will be wasted.

Large black rectangles are hanging from the ceiling at regular intervals, which Paul tells me are the ‘chilled beam’ coolers. These carry chilled water through a narrow pipe with an array of fins projecting from it, like the fins of a radiator. These chill the air around them, which becomes denser and falls to the floor, to be replaced by rising warmer air, causing constant cooling and air movement.

On top of the building will be a large solar array combined with a ‘green roof’— a living rooftop covered in plants. We discuss how these two things can work together, as surely both the solar panels and the plants need sunlight, but Liz assures us it’s been planned to work.

Green roofs apparently help to cool surfaces and the surrounding areas, while also lowering energy consumption, insulating buildings from noise and improving air quality — all of which means happier and healthier workers.

We’re unfortunately not able to go up onto the roof while it’s under construction, but Paul has another idea. He gets out his phone and arranges for us to meet some people in Tower 1 who’ll likely let us look at the view of the roof from their office. I’m about to discover there’s a whole lot more to this precinct than I realised.

The Daramu House tour officially over, Liz takes us back down to the construction office and signs us out. She decides to tag along for the Tower 1 visit.

We soon arrive and pass through the tower’s security gate, then rise up in the lift. The lift’s windows already give us a view of the roof of Daramu House, which is largely unfinished.

When we arrive at the office Paul was thinking of, I’m not taken to the window. Instead, I’m ushered into a meeting room, sat down and introduced to two people, Ted and Ashok, who wait expectantly for me to ask them questions. A little stunned and confused, I try to pretend as though I know why I’ve been brought here.

Slowly, as we get talking, I start to understand. I thought we were coming up here just for the view, but Darren and Paul saw an opportunity to add a little something special to my tour.

I’m high up in the management office of the largest commercial building in the Southern Hemisphere, part of a massive commercial precinct. I hadn’t really considered that a place like this would register very high in terms of sustainability credentials, but I’m learning that having two of Australia’s newest timber office buildings is just the beginning.

Buildings are responsible for 38% of all greenhouse gas emissions, with 18% from commercial buildings. Lendlease has aimed for a 20% reduction in embodied carbon (the carbon emissions intensity of producing a material) compared to standard construction practices by reducing the use of concrete, aluminium, glass and steel across the precinct. A 6-star Green Star as-built rating was awarded to Tower 2, making it Australia’s most sustainable high rise office building. The precinct as a whole was selected as a ‘C40 Cities Climate Positive Development’, one of only 18 projects worldwide.

Ted and Ashok are two of the operational management personnel for Tower 1. They take me over to a wall with four large monitors displaying digital images of the tower, along with cross-sections of each floor lit up in different colours. All the lighting, heating and cooling is controlled by a massive network of sensors throughout the towers, and from this office they can monitor it all, even seeing when a light has been left on or a secure door left open.

They tell me the windows are all clear glass, rather than tinted, to let in as much light as possible. All the lights are LEDs, and those nearest the windows dim automatically when there’s enough natural light, and solar blinds prevent too much direct sun entering the floors.

Looking out the window at the incredible view over the precinct, we can see solar panels on the roofs of the finished buildings — just a glimpse of the 6000 square metres of solar panels across all the roofs of the precinct — as well as more green roofs and green facades.

All the greenery is watered by rainwater or recycled water. Rainwater is harvested and stored in a 90,000L tank in each of the commercial towers, and a blackwater treatment plant recycles water for toilet flushing and irrigation.

Like the timber buildings, the towers all use the chilled beam technology for cooling, and pumping chilled water around uses far less energy than pumping air. It’s all driven by a ‘District Cooling Plant’, instead of separate cooling systems for each building, meaning even greater efficiencies.

And then there’s the waste.

We thank Ted and Ashok for their time, and head back to the lift, my stomach rising into my throat as we drop rapidly to ground level. After dropping off our safety gear back at the office, Paul and I say farewell to Darren, Liz and Katherine, then get back into the lift and head underground.

Many people know Barangaroo South by its three massive towers, but Paul tells me there’s a fourth tower lying on its side (or at least the equivalent space to one) in the precinct’s massive basement.

We pass through numerous tunnels and reach a large chamber filled with rubbish bins, their lids a range of different colours. Paul tells me that the precinct’s waste is separated into 19 different waste streams, with the bins colour-coded, and 80% of the waste is diverted from landfill.

A small side chamber has a weighing station for the bins. He tells me that 600 bins are weighed and emptied each day, and they’re constantly checking the contamination rates across the precinct. If a particular bin is repeatedly contaminated, then they’ll go to the source to try and address the problem.

All the retail food outlets use compostable packaging, and coffee cups are used as waste-to-energy fuel for a local cement manufacturing business.

Paul shows me a large chamber with a food waste processing machine, where food scraps and other compostable items are processed into pulp. He explains that it’s then taken off-site to an ‘anaerobic digester’ to produce biogas, which can be used to generate electricity. The remaining food residue is used on farms as compost.

I’m amazed that a commercial precinct would go to such lengths, and I ask Paul why they do it. What drives companies like Lendlease to strive for such a sustainable design? He tells me that it’s largely driven by the desires of the public and their commercial tenants. More and more companies want to have their offices in buildings with high sustainability ratings. Sustainability has become a core part of Lendlease’s values, and they pride themselves on delivering this in their building projects.

Paul takes me back to their ‘End of Trip’ facility, which I learn has around 1,100 bike racks, 1,200 lockers and 135 showers, plus a fresh towel service, to encourage the precinct’s thousands of workers to choose green travel options. There’s also a bike repair station, and Paul points to a nearby service desk where they’ll provide me with tools. I long to use the workstand to do some adjustments on my bike, but I’m running late for another meeting.

How quickly I’ve fallen into the patterns of a city office worker, organising back-to-back meetings. If I was to have an office, then I imagine working here in the timber buildings or towers of Barangaroo South would be pretty special. I unlock my bike — my current office on wheels — and wheel it out of the precinct, delighted by the direction that our city buildings are taking.

Huge thanks to Darren, Liz, Paul and Katherine from Lendlease, and Ted and Ashok from International Towers Sydney, for taking the time to talk with me and show me around.

Thanks for following my journey! Can you donate to help keep me pedalling forwards?