It鈥檚 been a year since the government announced that collaborative 3D building information modelling (BIM) would be required on all major government projects by 2016.
BIM is central to the reform of the government鈥檚 procurement strategy, which aims to slash construction costs by 20% by the end of this parliament.
The five-year timeframe is designed to give construction time to get to grips with this new collaborative way of working, both in terms of learning new processes and changing the adversarial culture of the construction industry.
So, after 12 months, has industry taken any steps towards the government鈥檚 BIM target? Undoubtedly yes, says Graeme Forbes, director of process and engineering at Kier. 鈥淚 would now be surprised if the industry doesn鈥檛 adopt BIM sooner than 2016. The last year has convinced me of BIM,鈥� says Forbes. 鈥淚t has exposed all the shortcomings of traditional construction.鈥�
Kier isn鈥檛 the only contractor that appears to be embracing BIM. Skanska, Laing O鈥橰ourke, BAM and Bouygues, to name but a few, are all using BIM to varying degrees.
But while larger companies have the resources to incorporate BIM into working practices what about pared-to-the-bone SMEs that don鈥檛 have investment capital to hand? 鈥淭he concern is the amount of investment needed in training, education and software will be a barrier that will disadvantage SMEs,鈥� says NFB spokesperson Andrew Dixon.
Resourcing BIM
So how hard is it to adopt BIM? Can firms afford to pass it by, at least until contractors start demanding it as part of the tender process? Those already using BIM suggest the benefits are too great to be ignored and that obstacles surrounding interoperability, contract risk and project insurance are surmountable.
BIM is a digital representation of a building, or piece of infrastructure, that ultimately can contain information covering its whole lifecycle, from conception to demolition. This knowledge can be shared between clients, construction teams and facility managers and can include data on costs, carbon, and maintenance schedules.
There are various levels of BIM and the first target is for central government facilities to be delivered using Level 2 BIM by this summer. This requires the production of 3D models by key members of the construction team.
Level 3 will be required by 2016 and is more complex. It is where data attached to the model, such as information on costs and, health and safety, can be used by everyone. Before this happens standards have to be developed to allow data exchange and legal issues on copyright and responsibilities ironed out. Working groups within the BIM Task Group are working on these.
BAM is already reaping the financial reward from working to Level 2 BIM, according to Chris Gilmour, the contractor鈥檚 design and marketing manager.
It has taken 3D models from the architect and structural and M&E consultants, and created one model in Navisworks. By overlaying the models it has been able to detect clashes. Identifying these issues at design stage rather than during the build means BAM has saved 拢350,000 on the 拢60m Leeds arena project. 鈥淭he arena would have been difficult without BIM,鈥� says Gilmour.
4D BIM
BAM also included time, so called 4D BIM (5D has costs while 6D models contain maintenance data). BAM was able to identify when and where subcontractors were likely to be working, and alter the sequencing to avoid overlapping trades, thus minimising delays and health and safety risks.
BIM forces collaboration between the construction team at an earlier stage, as teams have to ensure designs are compatible. It gives an earlier indication of likely costs and potential overspends.
This is a big benefit to Kier鈥檚 Forbes. 鈥淵ou can identify ambiguity, inaccuracy and workflow problems with 3D BIM. The 2D process is inadequate鈥�
Tim Cole, executive vice president for strategy at Causeway, says BIM allows the expertise of contractors to be taken into account. 鈥淭raditionally this doesn鈥檛 happen and it results in requests for information leading to delay and higher costs,鈥� he says. 鈥淐ontractors coming in earlier are more interested in getting it right because they would be sharing the risk鈥�
For Gilmour this offers BAM a major advantage when tendering for jobs. 鈥淲e use consultant鈥檚 early designs to create a model and identify issues to the client including ways we can save money. We鈥檝e won work on this basis,鈥� he says.
Both Kier and BAM feel contractors should co-ordinate the BIM as they have to work with a model that can be built. Contractors tend to add 3D models of components, or objects, when specifications have been chosen.
The objects can be built by the contractor or manufacturer, or they could be obtained from a BIM library. The NBS recently launched its National BIM Library and the BIM Store also has components for the major 3D packages from Autodesk Bentley and Graphisoft. In time costs and carbon performance could be added to these components and Aecom has just signed a deal with NBS with the intention of one day adding their data to NBS models.
Cut maintenance costs
One of the big drivers of BIM is to cut the costs of building maintenance. The idea is that the model will include maintenance information 鈥� 6D BIM - and will be handed over to the client or facility manager to help with scheduled maintenance. This has been pushed by Sellars at the Place at London Bridge, designed by Renzo Piano (see box) and Manchester City Council is looking at generating FM datasheets in the BIM model for each room at Manchester Central Library.
But is BIM just for the big boys? Will the small firms lose out if they don鈥檛 bust a gut to get onboard with BIM? Forbes doesn鈥檛 think subcontractors will necessary be disadvantaged if they鈥檙e not using BIM. He believes that the BIM model gives them more accurate information and a quantified schedule of works. 鈥淭here鈥檚 less risk 鈥� all the work has been done for them. It鈥檚 much easier to price.鈥�
Gilmour says BAM is helping subcontractors get on board BIM, and says many larger firms are already using it.
BIM is being adopted at a fast rate at BAM. It estimates 30% of its work will be in BIM this year, 60% in 2013 and 100% in 2014. The government target is having a big effect on the update of BIM in the private sector says IT consultant Paul Wilkinson. 鈥淚f you鈥檝e invested in software, training and new processes to meet the government target, you won鈥檛 want to use it just in the public sector, but in the private sector too.鈥�
The NFB鈥檚 Dixon says that many smaller builders will look at BIM more closely if local authorities start using BIM. Manchester City Council is pioneering BIM use on its projects including the refurbishment of Manchester City Library, to a 172-unit social housing scheme.
Here the council used a third party BIM provider and saved 拢150,000 through improvements in the programme, more efficient use of materials and certainty of cost, estimated the council saved 拢250,000 making a net saving of 拢150,000.
John Lorimer, the council鈥檚 capital programme director, is completely convinced of BIM. 鈥淚t鈥檚 sensible, mature, safe, it鈥檚 the future. I wouldn鈥檛 contemplate working in the industry and not using it. You will be sidelined.鈥� If other local authorities follow Manchester鈥檚 lead then SMEs may have no choice to gear up to BIM. The imminent results of a NFB survey will determine how far they still have to go.
Forbes for one, believes BIM is a worthwhile investment. He says BIM no longer needs intervention from government. 鈥淭here is now such a strong impetus that we don鈥檛 need a mandate from government for industry to adopt BIM,鈥� he says.
Case study: London Bridge Place
The proximity to a tangle of London鈥檚 transport infrastructure made The Place at London Bridge a very challenging building to design.
The 40,000 sq m building had limited supports because of Tube lines and escalators running below, so Renzo Piano created a structure that hung off the central core, rather like an upturned umbrella.
As the multidisciplinary engineering consultant WSP had to find a way to thread services through the building without affecting the strength of the core.
The BIM model helped WSP CAD technical manager Ed Kyte determine where openings in the beams could be positioned.
鈥淏IM allowed us to start visualizing,鈥� says Kyte. 鈥淲e were able to show the architect where they had to move a door or corridor to help with the services design.鈥�
WSP is the project co-ordinator and BIM consultant on the job. It handed over the model to Mace the contractor, which gradually replaced WSP鈥檚 generic objects for components such as air handling units with real specifications and installation models.
鈥淚f we found clashes, Mace as installation co-ordinator, had to resolve them. We were able to offer them guidance as we knew how it was originally conceived,鈥� says Kyte.
As well as assisting in clash detection through Navisworks, the data in the model also helped with co-ordination, cost estimation and sequencing. The model is also 6D, and contains FM maintenance information for the developer Sellar, which was the ultimate driver for BIM on the project.
鈥淲e are staring to link values to the FM information. Every valve has a reference number that links through to a schedule document,鈥� says Kyle.
鈥淔M can click on a valve and see when it was last maintained. Major pieces of kit can be viewed in 3D in an office environment, which means you know what health and safety equipment will be required to access the kit.鈥�
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