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Preparing for BIM

Sydney-based Project Surveyors transformed from a conventional surveying company into an internationally recognised firm ready to make the most of a data hungry development industry. 

The future of 3D modelling for development projects may still be shrouded in uncertainty in Australia, however, organisations like Sydney-based Project Surveyors are transforming their businesses in anticipation of the expected changes, and receiving international praise for it. Like Project Surveyors, many believe that it is inevitable that Australia will follow the likes of the United Kingdom, where it will be mandatory from 2016 for major new development projects to provide fully collaborative 3-dimensional BIM (building information modelling). The UK Government’s BIM Task Group describes BIM as “collaboration through the entire life-cycle of an asset, underpinned by the creation, collation and exchange of shared 3D models and intelligent, structured data attached to them.”

Such models are intended to be available to the various parties involved in the development process from design through to as-built, and cover everything from light fittings, building materials and services, all located with survey-accurate dimensions. Independent of the mandating of BIM is the strong international trend towards adopting comprehensive survey-accurate 3D models for development projects and facilities management, a task for which surveyors stand alone in having the skills for handling big data within small accuracies. In light of the available laser scanning technologies, software capabilities and the ability to collaborate across the internet, 3D modelling has growing advantages over conventional methods.

So when Castle Towers shopping centre in north-western Sydney planned to transform itself into Australia’s second largest retail centre, they engaged Sydney-based Project Surveyors to create a comprehensive 3D model of their existing facilities, despite having no legal requirement to do so. 

Project Surveyors is proof that conventional surveying businesses are uniquely positioned to make the most of this burgeoning field. Their work on Sydney’s Castle Towers shopping centre saw them take out the International Leica Award for Buildings/Heritage at the recent HxGN Live event in Las Vegas, and industry figures within Autodesk and Hexagon have highlighted the significance of the project.

John Reddington, national manager of laser scanning at C.R.Kennedy said it was an internationally significant project, noting that apart from a handful of projects completed in the UK, there has been no 3D modelling project as comprehensive. In completing the project and subsequently winning the award, Project Surveyors has devised new survey field methods and created new workflows. The company has acquired new modelling expertise and effectively transformed the business from one grounded in traditional survey practices into a business ready and able to meet the needs of the data-hungry development industry.

Castle Towers shopping centre

Project Surveyors’ Nathan Mr Milligan pointed out that it was the first time the organisation had ever done anything of this scale before “We’ve done many asbuilt work for commercial buildings and a couple of little shopping centres, but this was our first job of this size for sure,” said Mr Milligan. 

“A job generally for us might be a hundred to two hundred scans.” 

The Castle Towers project ended up being a much bigger undertaking, with a survey area encompassing approximately 375,000 square meters and 3,700 scans. Using the latest terrestrial laser scanning technology, it took 55 site days to fully scan the building, and a further 120 office days to complete the model.

“We literally had to scan everywhere,” said Mr Milligan. “We’re talking bathrooms, side stairs… the shopping centre has some fire stairs that just run and run and run, and you basically come out on the other side of the centre. Everything had to be done, loading docks, a bit of scanning on the roofs, all the structural elements...

“Every area we could get to had to be included in our models, so they had to be scanned.”

The approach

Before any of the scanning took place, a Leica Viva TS15 total station was used to establish an external control network around the premises, before traversing through the multiple levels to link the network indoors. Retro-reflective stick-on targets were mounted around the centre and coordinates were later adjusted to the external network.

“Because we established a good survey network before we started the scanning, we were able to keep it nice and tight so that we were getting data we could rely on,” said Mr Milligan. “It’s definitely necessary to have that survey control in place before you start your scanning, otherwise, even though the scanning might come together nicely, there’s no guarantee of the accuracy of it.”

Project Surveyors used the Leica C10 and P20 ScanStations, both of which achieve survey-accurate results through the use of compensators. The C10 ScanStation was used for the longerrange sites, such as in the multiple levels of the car park and common areas, while the Leica P20 ScanStation was used for rapid, short-range work such as in small shops and backrooms. A Leica Nova MS50 Multistation was also used to establish the control network and was used to perform ‘windowed’ scans in certain locations. To increase efficiency, the team avoided having to pack down and set up the tripod for each of the 3,700 scans by constructing ‘skates’ (pictured), on which the tripod would stand. This allowed field crews to easily reposition the tripod by simply rolling it to the new location, locking the wheels and resuming the scanning.

The work was also restrained by the logistics of conducting survey work in a fully functioning shopping centre. The six or so staff directly involved with the field work performed scanning day and night, as some tenancies would only allow daytime scanning. Other areas, such as common areas and car parks, were simply too populated to survey accurately and safely.

The scans were also supplemented by disto measurements and measuring tape readings in the inaccessible confined spaces, such as jam-packed backrooms of shops. Using these methods, the field crews were averaging no less than 60-70 scans a night being sent back into the office for modelling.

Handling all that data

The sheer scale added complexity to what was otherwise familiar survey work. “It’s work that we do on every job that we undertake,” said Mr Milligan. “It comes back to the size of it.”

The final file database for the project amounted to about 750 gigabytes. Managing that data provided yet another challenge, but as an established survey firm, Project Surveyors had a plan from the start: “We’d break it up so that we were separating the centre into floors, and the car park into different colours and levels,” said Mr Milligan.

“We had to break up the data, because when we try to take that data into Revit or AutoCAD, they can’t handle massive databases - so we would separate trading floors into levels 1, 2, 3, and then break those up into two or three different sections, depending on how large the footprint was.”

Even then, managing the survey of such a large and intricate building proved to be a challenge that Project Surveyors had to constantly wrangle, with some sections such as fire stairs being missed and forgotten due to something like a temporarily locked door.

“I think you’re always going to have issues like that,” said Mr Milligan. “But if you’ve got a good workflow in place and a good plan, you minimise that.”

3D modelling

Simultaneously, the team back at the Project Surveyors office was busy turning all of that raw point cloud data into an organised 3D model.

To assist them with the gargantuan task, Project Surveyors hired BIM spatial manager Andy Jackson, who was brought in from England to join the team for his experience in building information modelling projects in the UK. It was Jackson’s role to handle all the incoming data and oversee the 3D modelling of it all. Leica’s Cyclone 9.0 software was used to clean and register the point clouds and also publish 3D images for use in Leica’s TruView panoramic point cloud viewer. Revit 2014 was used to model architecture elements, while the features of Revit MEP was used to create pipes, plant, ducts, and other services to create a partial MEP (mechanical/electrical/plumbing).

Much of the modelling work was outsourced overseas, however, and while Project Surveyors has had success outsourcing smaller, simpler projects, they would opt to perform the modelling in-house in future projects of this nature.

“It’s hard to make sure everyone’s modelling to the same standards, so you’d find different people having different interpretations,” said Mr Milligan. “Ideally, we’d like to do a lot more of it with fewer people so that we can control the integrity of it and how it’s all presented. We also want to make sure we’ve got certain standards across the board, and if you’ve got fewer people working on it, you’ve got better control.”

Mr Milligan attributed much of the success of the project to Leica’s recently updated Cyclone software for point cloud data. “It allowed us to register it and process the point cloud data a lot quicker than we previously would have done it, so that was a significant development and something that I think made a massive improvement.”

Preparing for BIM

While not strictly a BIM project, the scale and comprehensiveness of the project has all the same elements and has seen the firm garner international attention from Leica and Autodesk. “It’s getting us a bit of a reputation as market leaders in this type of work,” said Mr Milligan.

It was John Reddington, national manager of Laser scanning at C.R.Kennedy, who described the work as an “internationally significant project.” 

“I don’t think there’s anyone in Australia who’s done something this big on a single project,” he said.  “And in world terms, you don’t get a much bigger building for a customer to pay to do a complete 3D model of the a facility.”

Mr Reddington also commended Project Surveyors for its ability to take on this new area of survey work. A few years ago, Project Surveyors was an average surveying company doing traditional work, such as topographical surveying, building plans, and setting out. Laser scanning, and now 3D modelling, have reshaped the business entirely. 

“It’s become a big part of the business, if not the biggest part of the business,” said Mr Reddington. “They transformed the business through laser scanning and through their own hard work in getting the expertise on the software side of things.” 

Mr Milligan said Project Surveyors is indeed positioning itself for the impending arrival of BIM. “I think it’s coming, and we would like to be considered to have a bit of expertise in BIM,” he said.

“I think we might be getting to the stage where a lot of buildings are designed in a BIM environment, and are being handed over as Revit models. Europe and the US are probably five years ahead of us.”

Uniquely positioned

Those with a background in surveying are uniquely positioned for this type of work, and the movement is driven by the desire for timely 3D data across the whole development cycle.

“Everything’s moving into 3D,” said Mr Reddington. “It’s not just surveyors: the architects and engineers are now demanding the data in 3D, too, so that surveyors’ traditional deliverable plans like 2D plans aren’t going to be much use to them anymore - the deliverable product is going to have to be 3D.

“Traditional surveying is changing and companies are getting into this new business area. It is a very profitable business area.”

Mr Reddington noted that while C.R.Kennedy considers surveyors to be the best positioned for this type of work, it is also supplying the most laser scanners to architectural schools, which are now adding 3D modelling to their curriculum. Mr Reddington believes it could go one of two ways: the architects might hire or even employ survey staff to carry out the control work while the architects themselves conduct the scanning and modelling, and the other scenario sees surveyors evolving much like Project Surveyors has done: adapting skills to include laser scanning and modelling and capitalising on the new opportunities.

“In some respects, I’d like to say it’s almost a call of action to the surveyors,” said Mr Reddington. “They must get on board BIM early to really control the market, because it is, at the end of the day, about providing spatial data.”

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