Description
Key Learnings
- Learn how to implement a BIM strategy for retrofitting buildings to save on material waste and cost.
- Learn about collaborating effectively across the globe using the Autodesk Construction Cloud.
- Learn about capturing existing site conditions using laser scan technologies to develop BIM data for structural analysis.
- Learn how to evaluate the amount of embodied carbon savings using the BIM data and using Autodesk Insight.
Speakers
- ALAraj (Raj) LalAraj has over 15 years' experience in the co-ordination and documentation of major infrastructure and building design, as well as BIM Coordination, and been involved with a wide range of infrastructure and building projects such as Metro stations, bridges, tunnels, shopping centres, warehouses, hotels, schools and high rise residential and commercial buildings, using various construction methods such as tunneling, piling and shoring, reinforced and post-tensioned concrete, precast concrete, and structural steel. He is an Autodesk Accredited Professional in Revit Structures, and is proficient in the use of ACC, Revit, Civil 3D, AutoCAD, Navisworks, ProjectWise, ReCap and Revizto software packages.
- Sam MacalisterI am an Architect & BIM technical specialist for Autodesk Australia based in Sydney, Australia. I have designed buildings in New Zealand, United Kingdom, Middle East, India & Australia working mainly in Healthcare, Education & Residential design.
ARAJ LAL: Hey, guys. Welcome to our case study about retrofitting buildings using AEC Autodesk Construction Cloud featuring our main project that we've delivered recently, which is the Quay Quarter Tower project. I've got with myself at the moment, Leonard, who's one of our associate structural engineers at BG&E. And my name is Raj, formally Araj Lal, Senior Associate Structures BIM at BG&E.
We're really-- this is us. So who are we? We're surf and turf. Leo is the surfer amongst us, and I'm the farmer amongst us. So we come from a bit of different things that we do outside of work, but that's us pretty much. We like to enjoy ourselves outside of work when we're not designing 50-story skyscrapers.
What we're going to try and go through today is the Quay Quarter Tower project, which has been a milestone project for both of us at BG&E. We spent a lot of blood, sweat, and tears on this project from roughly about 2015 onwards up till about 2022, when the project was officially opened. So what we're going to try and get through today is a little bit about BG&E-- who we are, what we do, as well as the Quay Quarter Tower project. Why is it so special?
You can probably see on my screen there, the Quay Quarter Tower project is actually right on the skyline of the Sydney Harbor. So it's quite prominent. It's quite special. We're going to also go through the design, the concept behind the design, why did we retrofit the project-- retrofit the building as opposed to complete knock down and rebuild. Then we're going to get through the design and construction challenges that we faced with the retrofitting a building of this size as opposed to knocking down and rebuilding it.
With that comes the sustainability savings that occurred by keeping a decent amount of the existing structure. We're also going to go through the BIM challenges and the BIM collaboration that we undertook on the project, which includes cloud collaboration, model federation, clash detection, building the existing model-- which was also a big hurdle for us-- phasing and design options. And then we're going to finish it off with the take of the project.
So who is BG&E? BG&E is a structural, civil, and engineering-- and bridge engineering-- construction firm, started about 50 years ago in Perth, Australia. That's our backbone of our business, is the structural engineering, the civil engineering, and the bridge engineering. But we also pride ourselves on our technical excellence over the years. And we've extended our reach into other disciplines, such as timber, facade, construction engineering, rail, digital engineering, sustainability, and water infrastructure, among others. So now we're a very rounded engineering consultancy, but our key principles still remain with our structural, civil, and bridge engineering divisions.
At the moment, we span across 17 offices around the world. We are completely 100% employee-owned, and 90% of our taskforces are all technical experts in their field. We do billions of dollars worth of projects all around the world. And we still manage to employ about 1,100 people as well-- technical people who are all around the world.
We started off in our humble beginnings, like I mentioned earlier, in Perth. But then we expanded over into Sydney, then up and down the east coast of Australia, in the Middle East, and in recent years, we've expanded into Europe, South East Asia, and New Zealand.
What is QQT? QQT for us has probably been one of the milestone projects of our career. We started it off, like I mentioned earlier, in 2015. We did the redesign of the concept back then. And then we sort of took ourselves into detailed design and then finished off construction in 2022.
Here's a little video showing you the magnificence and its beauty of the project. And I'm going to hand it over to my colleague, Leonard, to talk further into the design and construction challenges that we faced.
LEONARD AMBROGI: Hey, everyone. It's very nice to be able to be here and present this great project with Raj. And like Raj said, I was part of the team. I was one of the engineers working on the project, and then the last two years of the project, I ended up taking the lead and project managing the BG&E team to complete the delivery of the project.
I was intimately involved with the temporary works associated with this project. And it's been obviously the milestone in my career. And I like to say that everything is downhill after this project in terms of the engineering that I can possibly think I'll be facing in my career. But, yeah, great project.
What is QQT? So you've seen the finished product. One of the particularity of this project, I suppose, and what we're talking about-- one of the main subject-- is the fact that it's a re-adaptation of an existing building. So there was once upon a time another building on that exact same site. And the-- that's playing again, sorry. Next slide. That's the one.
There's a video that we like to play when we try and explain to people what the existing building was and where we are. And it's from a famous movie that I think everyone's going to guess as soon as I start the video. But the building is the one that you can see standing-- the first tall building on the left hand side of the sunset. I'm just going to let this video play, and I'm sure everyone's going to guess the movie straight away.
The reason we're playing this movie is because, believe it or not, it was filmed in Sydney. And one of the main scenes actually shows the building. There it is. Right at the back of the helicopter. This is the existing 50 Bridge Street high-rise building which we transformed into the new Quay Quarter Tower. There it is on the left. That was the existing building.
So like I said, one of the main features of this building was the fact that we re-adapted an existing building. This slide is to show you the old building on the left, which was completed in 1976. It was a 46-story building, one of the first high rises in the Sydney skyline. And on the right hand side is the current Quay Quarter Tower, which was completed, like Raj said, in 2022.
Now what happened in between? First of all, I'm just going to give you a bit of a taste for what the design features are. One of the main, I suppose, aspects of the brief that the architect that won the competition-- who was the Danish 3XN-- had to work with was to find a design that was going to blend into the beautiful Sydney skylight and harbor, because we're right in front of the Sydney Opera House and the Harbor Bridge. And you can-- on the east of the building there is one of the main features of Sydney as well, the beautiful Royal Botanical Garden.
So the twisting aspect of the building was also significant, as it was aimed at leaving that evening sun hitting the garden without shading it too much. And this is why the building twists towards the west at the top. And at the bottom, it starts with this twist being instead towards the east, and it provides views towards the Domain.
The idea as well is a stacked vertical village, so there's a whole concept about keeping a community feeling about these villages. They're all interconnected with the stairs and very large atriums. So it sort of all blends together to give this beautiful aspect that this building has.
The next slide is showing you just some of the main sort of aspects of the project. The project was 1.2 billion Australian dollars, which is about 780,000 US dollars. Developer is AMP Capital. The contractor was Multiplex. And the architect was-- 3XN was the main architect. BVN was the executive architect. And we, as BG&E, were the main structural engineers but also participated with the material engineering services as well as the construction engineering services and all the construction-related engineering and temporary works.
The building is about 215 meters tall, which there's about 51 stories. So we've added six floors to the original building. One of the main features is this cantilever that keeps growing on the west side of the building, which is the left hand side. So we've got some raked columns-- diagonal columns that go from the top towards the bottom, which you can't see there because of the facade.
We've got some thoughts-- it's about 14 floors that are hanging, so we've got some hanging columns that go from the tip of the building down and support the tip of the floors. There's obviously an irregular shape with this major cantilever that happened at each block, which was one of the challenges as well in terms of the construction of the building.
One of the obviously main features is the increase in the floor plan compared to the old building. So we went from 1,500 to 2,500 square meters. So very significant increase in floor-- and in floor space, with a total increase of 40,000 square meter, which is about 430,000 square feet.
We've got really large spans, especially in those internal atriums-- up to 15 meter span floor beams. There's about five basement levels. We had to excavate an additional level in the existing basement of the building. Five additional floors on top of the existing building. And one of the main features, which we're going to obviously expand on, is the fact that we were able to retain a very significant part of the building.
Next slide. So, what is the concept of how this all happened? The existing building-- as you can see on the left hand side on the animation-- was retained. 70% of the structure was retained. You can see how we then built the new bit around and in front of the existing building, which is that green part of the building that you can see. So there was a very complicated construction methodology, and with a lot of different work fronts on different parts of the building to obviously achieve this in the quickest fashion possible.
This slide dives a little bit into what the concept was. So we can see on the left hand side the original tower, which was essentially a very sort of ordinary square plan style building with a core-- which is your lift shafts-- in the middle, and the beams that go to the perimeter columns with a little bit of a podium on the lower levels where the building is a little bit larger. So this is the original AMP building that was built in the 1976.
On this diagram, you can see highlighted in the dark gray is the part that we have demolished. So we essentially-- as you can see on the next slide, which is essentially what we retained of the existing structure-- that we literally sliced the building vertically and then added to it. And like we said, we almost doubled the floor plates area. So it's really a one off. I mean, I don't think there's ever been a building of 46 stories that's been sliced and demolished like this vertically.
So how-- a little bit more into exactly what we kept, what we built. This is showing a floor plan. So you can see on the left hand side, the floor plan of the existing building. The part in gray is the part that we demolished. And essentially, we demolished anything that was to the left side of that red line, which essentially corresponds to the edge of the core lifts.
So on the right hand side, you can see how we obviously extended the floor plates, but not only that, you can actually see in that sort of darker blue color that we also extended the core of the building, which is essentially a solid reinforced concrete structure, and which is responsible to stabilizing the building against lateral loads, which was a main factor in the design.
Now everyone's going to probably ask themselves why we did that, why we kept the existing building, and wasn't it easier to just conventionally demolish the whole tower and rebuild from the beginning. But it turns out, saving the existing building was actually key into streamlining the construction process in terms of the timing. So we actually saved 13 months in construction time, which is a very big saving for the client, who can obviously in those 13 months, lend the building to its tenants.
We also saved 12 tons of embodied carbon by retaining the existing structure and not having to demolish more material than we needed and not having to actually bring new material that we didn't need and that we already had and that we could use. Not only that, but we also saved $140 million in construction cost. So, I mean, it was just a win-win. The sustainability side of it was also a big factor. And these three elements-- so the sustainability with saving the carbon, the timing of construction, and also the cost saving led to going down that path.
A little bit on the BG&E team and what it meant for BG&E in numbers in terms of the project delivery. We've looked into our books, and we saw that we actually spent 85,929 hours-- of labor hours between all the people that were involved in the project. We had 969 drawings produced. We had seven structural models and container files.
I mean, this is an enormous amount of drawings, and we're just talking the BG&E drawings here. We had demolition drawings. We had existing buildings drawings. We had the new structures drawings. There was 39 BIM modelers that worked on the project in different offices, so really from all around the world. 69 structural engineers-- again, from all around our offices around the world. So a huge team just in our own company, not to say the other consultants and people that participated to the job.
So I'm going to dive a little bit into the design challenges of QQT because it does have some really unique aspects. I mean, it's really rare to refurbish a building of that size. And obviously, when you refurbish a building, it means that you're keeping materials, and so you want to make sure that the structure that you're keeping is sound and is OK for another 50 years, which is what we design our buildings for.
We-- our structural engineers are liable for the next 50 years. So the only way we could satisfy ourselves that the structure that we were retaining was adequate was to test the building because as we know, between the design and between what builders realize on site, sometimes it doesn't quite coincide.
So we had to do a full material testing of the building, which included the structural survey of the actual geometry. We had non-destructive testing of the existing concrete elements. We had destructive testing. So concrete core tests, we did over 1,500 of them. We evaluated the strength of not only the concrete, but also the existing reinforcement. We also had some structural steel that we had to evaluate the strength of. We prepared the full concrete repair specification as part of our material testing services. So there was a really comprehensive study of the existing building which had to be done to satisfy ourselves that we could use the building and it was fit for purpose for the next 50 years.
One of the really incredible features of this whole project is how we achieved the construction of the new building and how we demolished and rebuilt. On the left hand side there's a bit of a time lapse where you can see how the front building is getting scaffolded, demolished, and then the structure-- the new structure is coming up. Again, whilst all the facade is being installed, we had about four cranes-- full tower cranes on the job at some point.
You can see on the diagrams how the demolition, which was one of the first activities that we started, was carried out on multiple fronts. We had the demolition of the podium structure, the demolition from the top-- so top down-- and also the demolition of the inside guts of the building within the front of the core, which in the activity number two on the top right here, you can see how there's a little blue piece of the core coming up. That's why we demolished that guts of the building that you can on the third image.
Then we had the jump structure-- always on the top right there-- which is essentially the new structure coming up, which at the beginning had to be essentially a standalone structure with its own stabilizing elements, as we hadn't still finished and completed the demolition of the building coming from the top.
On the bottom left, the first diagram, you can see how the new part of the building is now connecting into the existing and the demolition is further down, so we could then start-- as we were still demolishing towards the bottom, we could go ahead with the construction of the core and the building. So, to then moving towards the bottom right, essentially complete the building and top it up.
So there was really a multitude of work fronts. It was an incredibly complex construction sequence. We had a really sophisticated modeling. One of the main challenges from the structural engineering point of view was that you're dealing with an existing building which has had its life and all the long term effects of the structure have happened. The building has moved, has settled. And now you're attaching a new structure into it which has to move, has to settle with time.
So to take that into account, we couldn't just build a model of the finished product, but we had to, in our structural analysis model, build all the stages starting from the construction of the original building all the way up to the finished product so that we could capture all the effects of this time dependency.
The building movements was a huge factor being in the middle and the heart of the Circular Quay in Sydney. We knew that as we were demolishing the front part of the building and the center of mass of the building was moving south-- which is in the direction of the white arrow that you can see-- we knew that the building was going to move south as well. And then as we would build the new structure in front of it, we knew from our models that as the center of mass was then moving back towards the north side-- so the red arrow-- the building would move back north as well.
Obviously the model was one thing. But then on site, we had to satisfy ourselves by some monitoring of the building that we were within the predicted movements. And they were significant. At the top of the building, we were going back a couple of hundred mils and then forward another couple of hundred mils.
This was the order of magnitude, which in fact, takes me to one of the other main aspects of this building, which was the actual monitoring. That was very important-- on one hand because obviously we wanted to make sure that this incredibly risky activity was going as per plans, but also because as we were moving through the construction, we wanted to monitor the different structural aspects and parameters of the building to then refine more and more the design as we were proceeding with construction.
Some of the elements, devices that we used for monitoring are shown on the diagram on the right. The positional survey-- so your conventional survey that you do every so on, daily or weekly via targets that you put on the buildings-- tells you exactly where that specific floor, that specific target is moving. So that was one of the methods we used. It was telling us how much the building was shortening-- so the column shortening was a big aspect of the design, which we're going to talk about-- the foundation settlement, the floor distortion-- these are the sort of things that we could monitor with positional survey.
We had tilt sensors, which are essentially sensors that can measure the tilt of the building. That was a live monitoring, which meant that there were also trigger levels. And every time something-- if something would pass that trigger level, there would be people receiving messages on their phones. So it was live 24/7.
We had accelerometers towards the top of the building that was helping us monitoring and measuring the frequency of the building as the structure was being built and the construction was going ahead. Not only that, we can measure the damping of the building. That also was live 24/7. We had strain gauges to monitor deformation in some key critical parts of the buildings. We had anemometers to measure wind speed.
And last but not least, we had a physical plumb bob, which you could say is a bit of an old school device. And you'd think, why would you do that if you have all these fancy devices that I just talked about. But it turns out the plumb bob is actually the most accurate system that we could possibly use. And it was literally a piece of string with a big weight at the end of it. And we had this string running through one of the lift shafts for about 40 stories. And fixed at the top and at the bottom we had a scale on two directions, and we could see how this plumb bob was moving. And it was giving us really-- because we were able to correlate those readings with the positional survey, it was really giving us outstanding precision results.
So this is all the devices that we used. In the picture, you can see people standing on forklifts. This is what we did at some point to measuring the damping of the building, which is essentially the measure by which the building can come back quicker to its sort of still states as it's excited. We had measurements done at some point with people standing on forklifts and going back and forth at a specific rhythm to essentially excite the building so that we can then read what the damping value of the building was to then further refine our design. So there was really a lot of attention in terms of all the monitoring on this building.
So the digital twinning and rigorous condition assessment-- so this is where, like I was saying, with all the devices that we had, we were really able to refine the design as we were constructing. So it was really a world class for the condition assessment and the testing of the building throughout the construction.
Essentially those devices were giving us information on frequency-- natural frequency, mode shapes, and damping-- inherent damping values of the building, which were then allowing us to refine all our data in the model and fine tune the design to provide the best outcome to our client, and most of all, also to minimize any demolition of some existing structure that might have been considered weak initially but that we then were able to keep. So really maximizing the conservation of all the structure that we could.
Some of the temporary works-- this is just really a few photos to show you how much we dared on this building. There was a lot of temporary steel-- about 1,000 ton, we estimated, of temporary steel installed and removed to facilitate the demolition and the staging. You can see some of the braces for the existing structure and some of the really large voids that we created in the building. This was really allowing us to proceed with all these works without-- and, you know, being able to work on different fronts.
This is some photos showing some of the excavation works that we did, some really impressive photos showing how we excavated an additional basement in front of the existing building whilst it was still-- essentially those columns were still supporting 46 stories. And you can see how we carved the rock right in front of it. So a lot of effort in terms of all the engineering and geotechnical engineers and structural engineers in our team.
This is another main feature-- the construction of the cantilevers. We were able to come up with this solution of using the new structural steel to add minimum steel to form big trusses with the new structure to be able to support those enormous platforms that would form a platform to work from to build the first cantilevered floors. So really trying to, again, maximize the usage of the materials that we have without having to introduce new materials in that uptick of really looking after sustainability. So this is some of the impressive steel trusses that we use for those cantilever floors.
Last but not least, one of those major really challenges that we had was the fact that we had to stitch a new building to an existing building. Really, a building is alive. It moves. Concrete shrinks and creeps with time. So it moves. It literally shrinks. So we had an existing building that had gone through its whole life. It had shortened. It had creeped. It had shrinked. And then we're building a new building right next to it that has to shrink, has to shorten because of its own weight.
So as we build the new building, we can't just build it at the same level as the existing one because we know that the existing one is there and it's set, but the new one is going to shorten because of a series of phenomenons. So we had to predict as engineers where and how much we would have to build each floor above the target final level such that once the new structure had settled, we could essentially match the existing building's levels.
There's two types of shortenings. There's the short term, which is during construction as you build the new building because of its sort of elastic nature of the material. As you put mass on top of it, it shortens. And the foundations as well, they settle. There's also long term effects, due mainly to the concrete which creeps and shrink with time. So again, that participates to that movement that we had to take into account. So a huge challenge predicting those values and getting it right. But we had a really good outcome. Everything worked perfectly at the end. So it was a really big success.
The other feature we had on the building was a tuned mass damper. On the right, you can see what the tuned mass damper is about. It's essentially a big mass that we put at the top of the building to reduce the accelerations of the building under big wind events which can affect the comfort of people habiting the building.
When the mass-- as you can see on the video now-- is free to move as the building shakes, it actually participates in and it helps the building, damping those accelerations and therefore you don't feel that shake as much. So there is a huge 380-ton-- which is about 838,000-poound block of steel on one of the top floors of the building. There it is on the right hand side.
Some more site photos. I might just flick through those quickly. But you can see the type of works that we've done, the amount of demolition and what we've kept and how we braced the building, the huge voids that we created in the building. And on the right hand side, one shot that shows you all the platforms as the building develops its cantilevers as it goes up. So really, really an incredible working site with some really, really large challenges.
Moving into the sustainability now. So it's obviously one of the big outcomes of this building is how we actually saved a lot of embodied carbon into the building. It's something that we're really proud of now. It's a huge thing these days. I mean, it's really across every sector we're talking about sustainability and how we can have an impact on reducing carbon emissions. The building and the construction are responsible for almost 40% of global energy related carbon emissions. So our industry has a huge impact. So we are definitely responsible for trying to improve that.
There's targets that have been set by the United Nation Paris agreements in 2015 to achieve a zero net carbon emission by 2050. So as designers, we have a responsibility to do our best to help the industry in that process.
So just to give you some context on how a designer of a building can impact on sustainability and on saving carbon emissions. One return flight to New York from London-- that doesn't stay, but it's a document from IStructE, which is the English Institution of Structural Engineers-- so from the UK. So a return flight London-New York can save you 1000 kilogram of carbon dioxide emission. When you cut meat, dairy, and beef from your diet, you can save about 2000 kilograms of carbon dioxide emission per year. If you stop driving your car, you can save 3000 kilogram CO2 per year.
Now if 20% of the structural embodied carbon reduction is achieved in the building as you design it and as you occupy it, you can save 200,000 kilograms CO2 emission per year. So it's really another scale. Like, if you can act on really trying to be sustainable when you design a building, you can have a huge impact.
This is really to give you a taste for where the savings are in terms of all the life cycle of a building. That is from, again, the Institution of the Structural Engineers in the UK who have developed a paper which gives you a mean to calculate embodied carbon in the building life cycle. Now, as you can see, there's-- this sort of summarizes for a specific case of a given residential average building. But more or less, the different styles of building give you more or less the same measure.
But essentially it shows you the distribution of where the embodied carbon stands in the different aspects and the stages of the life of a building. The product itself-- which is essentially the raw material supply, transport, manufacturing-- so really the materials that you're going to use, the amount of the materials, and how you transport them and how you manufacture them to build the building. It's one of the main factors, as you can see. 50% of the total embodied carbon of a life cycle of a building is in that first product stage.
Construction process, which involves the construction activities such as running a crane which needs petrol, or transport-- you know, trucks coming in and out and delivering. That doesn't count that much in the scheme of things. You can see how it is between 4% to 5% in total. The use of the building and the operational stage of the building, that has another-- it's one of the other main aspects of the embodied carbon footprint of a building.
And then you have the end of life, which is essentially your demolition, disposals of material, deconstruction, transport. But again, that-- like the construction itself-- doesn't seem to have a huge impact. So obviously, we want to act predominantly on those aspects that have the major impacts, and one of those is the amount of materials that you use.
So sustainability-- the designer's responsibility. What can we do? We need to really have a sharper focus on the design, on regeneration of buildings, materials, looking at construction and procurement of materials. It's really important to think about all these things at the concept phase, so with your client, the developer. That's a really big part of our responsibility, is to educate our clients, make them aware that we have a responsibility to try and go down that path.
There's the structural design efficiency, of course. We don't want to be too conservative. The good engineer is the engineer that used the right amount of material-- not more than what he needs. And also educating your younger peers, that is another responsibility that we have as engineers.
So going down the path of re-adapting a building rather than knocking it down and rebuilding it-- so retrofitting, trying to reduce thereby materials and construction impact, using low carbon materials, recycled materials, timber, trying to provide a design that is also more durable. I have a picture of the Colosseum there. I happen to be from Rome, so I know that building very well. But it's all to say that we these days, as structural engineers, are liable for a building for a design life of 50 years, but really we should be thinking of buildings as structures that we want to have as long as possible. And anything we can do to achieve that, we should try and do it.
And then there's all the energy efficiency-- from mechanical energy point of view, water conservation, waste reduction. So less structural but still all our consultants, fellows looking at mechanical engineering, electrical engineering, hydraulic engineering. There's a huge impact there in the everyday daily life of the building usage that we can act on. And, yes, the smart design-- or designer-- can have an impact on all of this.
And I suppose looking into a little bit more QQT, like I was mentioning before, there is this carbon dioxide equivalent emission, which is really the measure that we use these days to try and quantify the amount of carbon dioxide that we produce and that we release in the air when we are in the process of building a building or using the building. One of the resources-- one of the informations that we use to provide a number to understand where does QQT stand in terms of carbon emission. How well did we do? How do we quantify that? What's our reference?
Now, there is an institution, which is called the London Energy Transformation Initiative, which is essentially a UK-- it's a network of professionals in the building environment. They have set targets to meet the European Union commitment to the 2050 zero net emission that was agreed. They have developed some essentially targets for the building industry to be able to have a reference and something to achieve in terms of their emissions to be able to meet that zero net emissions by 2050. They have set a target for 2030 for carbon emission, and the number is 228 kilograms CO2 emissions by meter square of essentially of habitable floor.
So with respect to that, in 2022, the QQT performance was-- and this is a number that was calculated by different organizations, including us. And we came up with the 226. So essentially, we met that target that the LETI has set for 2030. We're very proud of that. We've met that target eight years ahead of schedule with the materials and the technology that we have now in 2022, rather than the ones that we will have in 2030. So really an outstanding result, way ahead of its time.
So here, really stressing the importance of trying to go down that path. Consider refurbishing a building before you're thinking of just knocking it down and rebuilding it. So again, in total we've calculated that we saved 12,000 tons of embodied carbon-- which, just to give you a perspective, it's equivalent to 12,000 return flights from London to New York. So really, really proud of this achievement.
And we hope that we can set a bit of an example for everyone in the industry moving forward. And that has essentially allowed us to win the achievement from the Green Building Council of Australia, the six star rating for sustainability. So, something that we're really proud of.
I think this is it for my part, so I might hand it over to Raj again.
ARAJ LAL: Thanks, Leo. Thanks for that. So basically, when we talk BIM and collaboration, we're talking about the differences Autodesk made to our project and the significant role that they played to help us deliver a project for this scale and magnitude.
When we started the project back in 2015, we had no way of actually collaborating with our other offices besides using our servers, which was painstakingly slow when we're talking about using our Middle East offices, your UK offices. So for us, we started off on the Revit Server on this project, which was-- as you can imagine, was pretty painstakingly slow. At some stages, sometimes we'd press synchronize in Sydney, and by the time Perth jump online-- or, sorry, Dubai jump online, it takes about half an hour to save any work back to the Revit Server. So for us, it was a bit painstakingly slow.
So then Autodesk released their first iteration of the Construction Cloud, which was BIM 360. And for us, it was a game changer. We could work collaboratively on a cloud environment hosting our hub mainly in Sydney but then working with our other offices in the Middle East, all around Australia, to be able to pull together the 39 resources, the modelers we needed to be able to deliver a project for this scale.
In Sydney, for us to just go out there and hire 39 modelers off the street-- yes, we could have probably found them, but if we have the resources in-house across the global BG&E business, why not use them? So the cloud collaboration was a game changer for us. And moving on from-- so we took it on pretty early, back in 2015. But now we're in 2023, and at the moment we've got over 200 active projects worldwide that BG&E are currently working on which is hosted on the Autodesk Construction Cloud.
Now, the challenges of BIM on this project-- because the building was built in the 1970s, all we had to go off was a few different things. So we had site investigation, which we did taking photos. Some of the photos you can see there on the screen. We also had the existing drawings, which was scanned copies of the original, which were saved in council archive somewhere-- all in feet and inches. So for you American folks, that's probably OK. But for us Aussie blokes, it's a bit hard, so we'd have to go through and convert them all to millimeters, metrics, to be able to then build an accurate version of the model.
But then we couldn't actually just go off the existing drawings because of the changes that had gone through throughout its life cycle. So as you can see in that top right corner, some of those beams were tapered on the end, and we wouldn't know that off the drawings. It's a bit hard to tell. So our site investigation was very important.
We also had a lot of 2D survey. Back then, 3D surveys were relatively new-- wasn't as used throughout the industry. The fun fact we actually have is the image you can see on the left there was actually of the set out of the core at each level. We actually had a surveyor sitting on top of a lift going floor by floor, measuring out each core lift so we can accurately set out the core relative to itself, pretty much.
We couldn't just run a wall all the way up because as you can imagine, when it was built in 1970, there wasn't really any jump forms that were built floor by floor. So the complexities of it-- it was sort of rotating as it went up slightly. So 2D survey played a huge part. We had thousands of them.
We also had few point cloud surveys. Point cloud surveys were also relatively new-- wasn't that used throughout the industry. So we had bespoke areas that were point cloud surveyed so we could use as another checking mechanism, which we use Autodesk recap for. Internally, we did a lot of clash detection using Navisworks to be able to be comfortable with ourselves that our design is clash free as much as possible.
Phasing and staging was very important. Like Leo said, we retained the existing building. So to be able to accurately document this, we had to actually phase them inside of Revit and distinguish them accordingly, as you can see. The fun fact also on this image is, that building at the front there was actually the first high rise of Sydney. It's heritage listed. So we couldn't touch it. Hence, why also the rotation of the building was designed that way as well to sort of peer past that existing tower.
So the demo stage you can see there on the image on the right-- columns on the outside, like Leo mentioned, core on the inside. And then we went to basically vertically cutting like a piece of cake-- essentially cutting the building, a third of it off-- demolishing, and going actually down another level to build another level basement, and then building all the way up in the final case.
So phasing and staging inside of Revit was very heavily used. We also went through at the early stages of the project-- the western facade, like Leo mentioned, there was a raking column pretty much. Because the building moved in such a way in the five blocks, there was no way of actually transferring the load in a vertical sort of scenario. So we had to come up with a few different options of actually doing-- the bracing the Western facade. So we went through a few iterations. It was very important from an aesthetical perspective but also from a structural engineering perspective.
So design options inside of Revit was used quite heavily to be able to go through the different options. These were the last three that we ended up with. I didn't want to show you all the options we had. But those were the three that we sort of ended up with. And we actually settled on the one on the right, which basically gave us an inclined column from the basement all the way up to level 50. And as you can see from one of the site photos there, some of them actually crossed over, so we actually had these knuckles where we could cross over and pass [INAUDIBLE] through. So it was a bit of a detailing nightmare for us. But we got through it, and it got built.
Some additional facts to round out our prezo. We actually ended up modeling 27,000-- close to 27,500 modeling elements, existing of which we retained about 7,700. We demolished about 6,800 of them. And we modeled close to 13,000 new elements, which adds up to that 27,500 that you can see.
We used over 120 view templates. So as you can imagine, with that many view templates inside of Revit working with-- at any given time close to-- at any given time, you probably have 15 modelers working on the job. Throughout the life cycle we had 39-- but not all at once, obviously-- but say 15 modelers working on at the same time. From a model management perspective, which was where I was quite heavily involved as the lead modeler on the project, it was very critical to actually manage the view templates, make sure that the models are behaving the way they should, the right view templates are getting used, the correct drawing scales and everything that was getting used. So model management was very key.
So sort of to round off our presentation, the takeouts-- collating what Leonard said and some of the stuff that I've said. The major savings for us was in the cloud collaboration, the reduction in embodied carbons, the saving of construction and time cost, and also extending the asset life cycle-- life of the project. To be able to deliver all of this, it's very important to actually understand the existing structure and what it's made of. And to be able to do that, the study that we had to go through to actually understand what the existing building does was very important before we tacked on anything to it. And the reuse of a structure is very important to be able to save the embodied carbon that we did on the project.
Our materials team played a huge part to actually help us understand how the existing building behaved. A fun fact is, back in 20-- sorry, back in 1970 when they actually built this project, there was no concrete boom pumps that could pump up 50 levels. They actually carried the concrete up by hand in buckets.
So when we actually did those cores that Leo was talking about, sometimes you'd core and you'd get 40 MPa and you're sweet, you're happy. Happy days, can continue designing. We can build this thing. But sometimes you'd core literally right above it, and you'll get just water-- just slush. Because by the time the blokes back then in 1970 when they built this thing, as they carried the buckets up the stairs and then finally poured it in, the aggregate would move to the bottom and it'd just be slush at the top.
So those little challenges that we faced, we wouldn't have known that unless our construction engineering team was involved-- and, sorry, our materials testing team was involved to actually core hole test numerous times of over 1,500 core holes.
So another takeout, like Leo mentioned, was as designers, we should be designing for carbon the same way we design for speed of construction, occupancy requirements, and cost, and time savings. So it is another factor that should play a heavy part in the design-- and client and community expectations for a better environmental outcome.
The other thing that we haven't mentioned up till now was the 100 or so awards that we've won on this project. I've just put a few up there for you guys to look at. We actually were awarded the Architectural Festival Award for 2022 as the world's best building of the year. We won the International High-Rise Award for 2022/2023. We actually also won the Best Office and Business Project by MIPIM as well as Project of the Year by Engineers Australia, Development of the Year by Urban Taskforce, and so on. Tall Buildings Conference Tall Buildings Award for 2022 as well.
So, so many awards, so many-- we can't take credit for all of it, but we'd like to think that we played our major part in it. To round off our presentation, we wanted to finish off with our Sydney landscape. We're very proud of the city that we live in. We're very proud of our project. And every time any of our family come or any of our friends come from overseas, I'm very proud to say I've worked on the project, and I'm sure Leo is as well.
So with that, I'd like to round off our presentation. Thank you very much, guys, for taking time to be part of our presentation, letting us showcase the beautiful work we've done over the years. I really appreciate it. And hopefully you guys all have a good day.
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