Design and Build Procurement in the Context of BIM and the Government Construction Strategy

Jane Foulkes
Building Information Modelling (BIM) is not new. However, since the publication of the UK Government Construction Strategy in May 2011, and the associated promise to deliver all Government projects in ‘Lightweight’ BIM on its projects by 2016, BIM has gone viral.

Building Information Modelling (BIM) is not new – it has been around since 1987, but the Construction Industry has been slow to catch on. However, since the publication of the UK Government Construction Strategy in May 2011, and the associated promise to deliver all Government projects in ‘Lightweight’ BIM [1] on its projects by 2016, BIM has gone viral: clients, consultants and contractors are waking up and embracing the challenge with open arms, and, it would seem, every day, the Construction Industry announces another conference, webinar, or CPD series on the subject.

This sudden stream of consciousness was reinforced in January 2012, by the Government Chief Construction Advisor, Paul Morrell, who stated that BIM is now on an unstoppable course, adding, “There will be spectacular change - we are only just beginning to understand the scale of what can be achieved and the amount of waste that can be eliminated from the system."

So what are we all getting so excited about? BIM is unquestionably more than just 3D modelling and building fly-throughs; it promises to change the way we work and the way in which we procure buildings with collaborative, integrated working processes that will revolutionise the construction sector, redefining the relationships between construction professionals, and driving through cost, time and material savings at every step of the way. BIM is going to be particularly beneficial for Design & Build procurement, and the best way to demonstrate this is to illustrate the benefits at each step of the project life-cycle.

Typically in the traditional pre-construction Design & Build scenario, the contractor receives a set of Employer’s Requirements documents and from this information he has to develop his design, arrive at a price and submit a tender. In reality, this process often fails because of the insufficiency of the documents provided – the requirements are unclear, elements are missing, scope is not adequately defined, either because the documents are weak in themselves, or because the client has not effectively communicated his requirements to his design team. What results is either a scenario where the price and programme are fixed and the building is delivered to the client and fails to match the client or end users’ expectations, or alternatively the building process is subjected to multiple changes at great cost, both financial and time related, often with compromises to the design which could have been avoided through greater clarity from the outset.

Often clients are not experts in the construction process, and it should not be necessary for them to have the skills needed to interpret 2D CAD drawings. A client receiving a design proposal as a BIM model can see the design in 3D, and walk through the model to verify that their outcomes will be met when the asset is built.

A BIM model changes this process and has the potential to address some of the shortcomings. Often clients are not experts in the construction process, and it should not be necessary for them to have the skills needed to interpret 2D CAD drawings. A client receiving a design proposal as a BIM model can see the design in 3D, and walk through the model to verify that their outcomes will be met when the asset is built. If any of the client’s requirements have been misinterpreted this can be picked up, corrected and fully costed far more easily than would be possible when construction begins on site.

As the design of the asset progresses, increasingly rich information can be embedded into the model. Even at early stages in the design the model can hold much of the information which would previously have been stored in a fragmented manner across multiple schedules and documents. This is important because the first phase of the project sets out the framework for all of the information on the detailed elements of the building, from initiation through to the end of a built asset lifecycle, including its demolition. Working with a fully co-ordinated BIM model means that this library of information can be accessed, changed or added to at any stage of the job, becoming more and more robust as the designs are developed. The adoption of information protocols such as BS1192 help to ensure that information in the model is well managed and that control over ownership is maintained when information is co-created and shared.

So, the contractor receives a BIM model and begins developing his more detailed proposals for his tender submission. The value proposition for the contractor at this stage is clear: he has a model which contains a full set of data from each stage the project has already passed through, from which uncertainty and risk have already been reduced, problems have been worked out, simulated and analysed, which together avoid potential impacts which would traditionally bite later.

Contractors working with BIM in the US, where its use is a lot more advanced, confirm overwhelmingly that one of the greatest benefits of BIM from their point of view is the improved collective understanding of design intent.

Contractors working with BIM in the US, where its use is a lot more advanced, confirm overwhelmingly that one of the greatest benefits of BIM from their point of view is the improved collective understanding of design intent. BIM can help integrated teams push more of the key decisions to the earlier stages of the process, allowing for smarter designs that capture a more detailed view of the entire project. This leads to greater professional satisfaction with project outcomes because predictability and improved performance are instrumental in developing a positive outlook on projects; there is better multi-party communication and understanding from 3D visualization and a model has been cited to be ‘worth a thousand drawings’.

In the pre-construction phase of the Design and Build procurement process, BIM also gives the Main Contractor the advantage that sub-contractors from every trade are able to input critical information into the model before beginning construction. As this is a relatively new supply-chain requirement, in the future, libraries of technical BIM data will be standard offerings from manufacturers and subcontractors, and should ensure that components fit correctly when they arrive on site. It is still early days for BIM adoption amongst sub-contractors; however as BIM compatibility becomes more common in specialist software used further down the supply chain the benefits of information integration will increase.

In addition, BIM creates other efficiencies for the Design & Build contractor: there is huge potential to cut down on rework, because the clash detection functions iron out conflicts in the model information, which saves design time, as well as obviating rework on site later. BIM should make design teams far more productive, especially as proficiency increases with use. This will enable the contractor to realise savings on professional fees.

By the end of the contractor’s design phase a fully developed model can be made available which then reaps the most obvious and dramatic benefits of BIM. With the vast majority of a project’s cost dedicated to the construction phase, real savings of time and money can be experienced on site.

By pre-planning, sequencing and reducing conflicts and changes during construction, contractors can avoid many of the mistakes that erode budgets and schedules. BIM can bring clarity to a complex project, and given that effective coordination brings value, contractors should see more opportunities to realise benefits as the level of complexity increases. With greater confidence in the co-ordination process, many contractors are likely to push for more prefabrication of systems and other building elements to help ease schedules. At the highly automated sophisticated end of the market, there are already opportunities for the model to link with machines in factories which produce off-site modules driven by the information stored in the BIM model. Other value propositions are that waste can be minimised on-site because ordering and take offs can be more accurate, and products delivered on a just-in-time basis rather than being stock-piled on-site.

Used to its fullest extent BIM should also deliver on improved job site safety, faster regulatory approval and vastly improved commissioning and project close-out. If cost and programme information are also tallied with the model, there is scope for more accurate monitoring and easier re-sequencing, as necessary. Upon project completion, the data and model outcomes can be used to ensure optimal asset performance, and it will be clear as to whether systems are operating as they should, and whether they have been maintained adequately. This should lead to fewer issues being blamed on the contractor post completion. Finally, there is the potential for reduced claims, disputes and conflicts: the more questions you can answer up front, the more you can eliminate the grey area that will cause problems later.

BIM offers clear advantages to both the public and private sector client and the contractor, particularly when the contractor is responsible for the design, but it is not a panacea for all industry ills.

It is now 15 years since the launch of the Egan report, and disappointingly the Government Construction Strategy still alludes to the same industry issues: a lack of value for money, a lack of co-ordination, a lack of programme reliability, and a lack of innovation and collaborative working. BIM can certainly help with the 20% cost savings required under the Strategy in public sector procurement, but it will take a while for this to become evident. BIM offers clear advantages to both the public and private sector client and the contractor, particularly when the contractor is responsible for the design, but it is not a panacea for all industry ills. Other pieces of the jigsaw need to fit into place including an intelligent client, early contractor involvement and soft landings, as well as a confirmed work stream and a willingness to emerge from our silos. BIM, however, is a 'unifier' and could conceivably push the industry in the right direction. Watch this space. 

 
[1] (Lightweight BIM is level 2 with all project and asset information, documentation and data being electronic, but excluding programme and cost information)

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