The belief that BIM technology is unaffordable is an “urban myth”, according to the head of technical information for Europe’s largest construction project.
The AU $27.5 billion Crossrail project – London’s first new underground railway line in more than 30 years – will increase central London rail capacity by 10% when it is completed in 2019. Tunnelling started in 2012, and construction is now 75% complete, with the line due to open to passengers in 2018.
The project has been hailed as a major driver of BIM processes, with managing company Crossrail Ltd aiming to make Crossrail the first major infrastructure project to fully realise the BIM lifestyle concept.
Crossrail’s Malcolm Taylor – who was recently invited to Australia by technology provider Bentley to speak about BIM – says the sheer size of the undertaking meant working in the construction industry’s traditional silos was going to be impractical.
“It was just too big a project to be undertaken by one designer, and we knew we were going to have 25 designers,” Taylor says. “We're talking about soaking up most of the UK design capabilities. So we were going to have a lot of people, and we had to figure out how that was going to work.
“We used a British standard, BS 1192, that we helped develop, which was all about figuring out a way in which multiple parties, multiple organisations could actually operate and work together in a CAD environment. That set the scene for the concept of collaboration in common data.”
Since planning began in 2008, about 1 million CAD files have been created, approved and integrated within a centralised, 3D BIM information model.
Taylor says he often hears people describe BIM as “a big investment” – however, he argues that is not the case, particularly when viewed from a whole-of-life cost analysis. One of the greatest advantages of working in the BIM environment is that the model becomes a “single source of truth” for the project, which results in reduced errors by ensuring only the most appropriate version of models, drawings and documentation are used.
“It may be a little costly and cost you a little bit of time initially,” Taylor says. “But once you're into it and you've adapted and you understand what it means to be working in a coordinated 3D world, the value that you add is so much better.
“When people say to me, ‘Yeah, it's a big investment’, normally it’s people who don’t really understand what you actually invest in.”
“It’s an intellectual investment in changing your processes of working, investment in changing how you do things. You're still buying computers, you're still buying software, but actually that's a small part of the cost. The difference between something that's going to do BIM-level two or BIM-level naught is minuscule.
“People talk about training costs. Again, that's all very small.
“That's why it is an urban myth that BIM costs more.”
For a project the scale of Crossrail, the savings from using BIM have been mind-boggling.
“Instead of having one application for asset information, one application for document management and one application for contract administration, all our contracts are managed through workflows in the same database,” Taylor says. “That saves us up to £10 million a year just in IT costs alone.”
The accuracy afforded by using BIM’s 3D models has meant Crossrail has been pushing the boundaries of what is possible. The "Eye of the Needle" is a name that the contractors gave to a place at Tottenham Court Road station where the new tunnel needed to go over an existing Northern line tunnel and at the same time under an escalator tunnel, with less than a metre clearance from each.
“The owners of all that infrastructure had to be persuaded that what we were doing was achievable and feasible,” Taylor explains. “It was our information world, really, that did that, and people could see that it would work.
“If they had said no to that, we'd have been probably costing the project another £100 million, because we would have had to have gone at least another five to eight meters deeper. So it saves all sorts of costs.”
International BIM Object Standard
In 2015, NATSPEC, the National Building Specification UK (NBS) and Masterspec NZ agreed to work together to create an International BIM Object Standard using the NBS BIM Object Standard as the starting point. In December, an initial draft was sent to a number of industry experts in Australia and New Zealand for review.
The second draft, including guidance notes and supporting information, is scheduled to be widely circulated for review and consultation within the Australian, NZ and the UK construction industries in April.
The Standard will consist of a core document that includes all items that represent a common approach, plus individual national appendices to accommodate local needs that are the inevitable product of differences in building and procurement practices, building products and regulatory frameworks.