Stephen Cousins searches for hard evidence of BIM’s benefits.
Client interviews carried out by BIM+ have revealed little tangible evidence of reductions in overall project outturn costs or project delivery times. This was viewed as being due to the difficulty isolating the specific impact of BIM on projects, versus other factors, and the relative infancy of many projects utilising BIM.
As David Walters, project manager at Argent, responsible for developing and implementing Argent’s BIM strategy on the King’s Cross site in north London, summarised: “It is very difficult to measure the benefits and savings exactly. A lot of it is anecdotal and there are only certain points where you can measure those savings – and many are confidential, which makes things very tricky to report on.”
The key benefit of BIM, expressed by most clients, lay in its 3D modelling aspect, which provided greater visual clarity on projects to enable key decision makers, end users – and in some cases the general public – to understand the finished asset and its impact on the local context. In addition, most agreed that BIM’s ability to improve collaboration and data sharing had made construction design and delivery phases more effective and efficient.
There was also general consensus that the technical accuracy of a federated BIM model, and related functions such as clash detection, have helped achieve a higher level of clarity faster on projects, eliminating remedial or abortive works during construction.
For instance, Karen Alford, BIM and GSL programme manager at the Environment Agency, said: “On projects carried out with a fully integrated model, key advantages were clash detection – we expect suppliers to do that at detailed design stage – and having visualisation fly-through models, to make publicly available to show what is going to happen on schemes such as the Shoreham flood defences or Boston barrier. These make detailed engineering solutions understandable by a wide range of people.”
Argent also reported that BIM had helped drive more space-efficient buildings, tightening up designs for floor areas, cores and riser spaces, translating into more lettable space.
And one development, project managed by Turner & Townsend, running optioneering exercises in BIM to optimise and reconfigure spaces, helped free up an extra 10% of lettable space for the client.
But George Mokhtar, BIM lead and associate director, Turner & Townsend, pointed out that the financial benefits to the client were mainly in shrinking risk exposure: “Generally speaking, basic BIM processes will provide quality coordination and clash detection – as a result we have seen a significant reduction in the risk pot. And when it is time for contractors to bid for a project, when we demonstrate that reduced risk, they in turn reduce their fee, which can be significant, in the millions of pounds.”
At Waitrose, Andy Smith, general manager of future planning, perceived value that was hard to measure in financial terms: “I can’t see massive cost reduction at the moment. Even so, there is so much value in the data we get from the BIM process. There is productivity value for the consultant design team, information value for the FM team.”
But most clients viewed themselves as still establishing the foundations of a BIM approach, with a view to reaping the benefits at a later date.
Matthew Richardson, architect and project designer for McCarthy & Stone’s south west region, said: “We can see that the benefits of BIM are going to be tremendous, but we have taken a cautious approach to make sure we don’t jump in and find we need to change our approach.”
And the Environment Agency’s Karen Alford added: “We will be learning a lot this year, and our suppliers across industry will be gaining an understanding of what it really means and the opportunities they can bring to projects. We are seeing positive responses from suppliers and evidence of them thinking about and doing better integration of modelling and data management.
“I anticipate us seeing savings coming through next year, but it is difficult to say at what level.”
I can’t see massive cost reduction at the moment. Even so, there is so much value in the data we get from the BIM process. There is productivity value for the consultant design team, information value for the FM team.– Andy Smith, Waitrose