Since the use of building information modelling (BIM) was announced as mandatory for all public sector construction projects by 2016, there has been, as is always the case with new government-backed initia-tives in UK construction, a lot of debate as to the usefulness of the process. Initially, BIM was poorly sold by the UK government, giving the impression that it was just about expensive systems, with case studies emphasising the technology involved instead of the opportunity to promote greater collaborative working. Consequently the uptake of BIM has not been as rapid or widespread as was initially hoped.
BIM is both a new technology and a new way of working. BIM is a system that has been around for a while in manufacturing and engineering industries, and is now beginning to make an impact in the construction sector. At a strategic level, BIM offers the capacity to address many of the industry’s failings, including waste reduction, value creation and improved productivity. The early involvement of project managers in the design process enables increased consideration for constructability and costs as design decisions are being made.
The improved reliability and consistency of BIM-based designs can lower construction costs by enabling many components to be prefabricated off-site in advance. Prefabricated components, by virtue of being made in controlled
factory environments, are typically lower cost and lower risk in that unpre-dictable field conditions are avoided. See Chapter 3 for further discussion of this point.
Team members responsible for schedule planning and cost control can use the information in the composite project model throughout the construction process to measure the impact of design changes and field conditions upon the predicted schedule and budget. Changes to the BIM model can be assessed to generate updated schedules and budget predic-tions, enabling project managers to better plan and allocate resources in the day-to-day operations at the construction site. In project manage-ment, establishing BIM on a project requires a client who understands the concept of upfront costs in return for future benefits; it also requires a good BIM protocol and a procurement strategy that inhibits silo thinking. The largest single barrier to exploiting BIM is the lack of awareness. Clients are frequently unaware that they can have a major influence on the delivera-bles from a project. BIM has the potential to impact every aspect of project management.
The project manager may need to guide a client through the business case for adopting BIM and the required changes to skills, roles and respon-sibilities. From a skills perspective, BIM is ‘business as usual’, with the same processes and controls except for a modified management informa-tion system / document protocol, modified roles and responsibilities and modified procurement strategy. The role of BIM manager should be con-sidered together with the responsibilities they would adopt. The primary issue for project managers is the management, control and interfacing of a data-rich environment, which depending on the maturity level, may all be heavily integrated.
The process of implementing BIM moves away from conventional word processing and CAD into the increased use of common standards and product-oriented representations. BIM changes the emphasis by making the model the primary tool for documentation, from which an increasing number of documents, or more accurately reports, such as plans, schedules and bills of quantities may be derived.
As was alluded to earlier, BIM involves more than simply implementing new software: it is a different way of thinking. Successful BIM requires a move away from the traditional communication channels, with all parties including architects, surveyors and contractors sharing, and effectively working on, a common information pool. This is a substantial shift from the convention, where parties often worked on separate information pools using several different (and usually incompatible) software packages. In essence,
BIM involves building a digital prototype of the model and simulating it in a digital world. BIM provides a common single and co-ordinated source of structured information, the BIM model, to support all parties involved in the delivery process, whether that be design, construction and / or opera-tion. Because all parties involved with a BIM project have access to the same data, the information loss associated with handing a project over from design team to construction team and thence to building owner / operator is kept to a minimum.
A BIM model contains representations of the actual parts and pieces being used to construct a building along with geometry, spatial relationships, geo-graphic information, quantities and properties of building components, for example manufacturers’ details. BIM can be used to demonstrate the entire building lifecycle from construction through to facility operation at various levels of detail: 2D, 3D, 4D. Therefore, BIM provides a common environ-ment for all information defining a building, facility or asset, together with its common parts and activities. This includes building shape, design and construction time, costs, physical performance, logistics and more. More importantly, the information relates to the intended objects (components) and processes, rather than relating to the appearance and presentation of documents and drawings.
More traditional 2D or 3D drawings may well be outputs of BIM; however, instead of being generated in the conventional way (i.e. as individual draw-ings), they can all be produced directly from the model as a ‘view’ of the required information. BIM changes the traditional process by making the model the primary tool for the whole project team. This ensures that all the designers, contractors and subcontractors maintain their common basis for design, and that the detailed relationships between systems can be explored and detailed in full. Working with BIM will require new skills and these will have to be learned from practice.
BIM is not a silver bullet – it is just as possible to produce a poor model, in terms of its functionality, its constructability or its value, as it is to produce poor drawings, schedules or any other, more traditional form of informa-tion. Also, in the absence of any pro-active collaborative management effort, models may end up being prepared to suit the originator as opposed to being structured and presented with the design and construction team in mind. Ensuring that there is an agreed structure and exchange protocol in place to suit all parties will improve certainty, confidence and consistency.
By moving to a shared information model environment, project failures and cost overruns become less likely. BIM certainly means having a better under-standing and control of costs and schedules, as well as being able to ensure
that the right information is available at the right time to reduce requests for information, manage change and limit or even eliminate unforeseen costs, delays and claims and thereby aiding project management at all stages.
Clients are often in the best position to spearhead the introduction of BIM. Understanding the value of building information and its impact on the client’s own business is leading many clients to require BIM to specify the standards and methods to be used in its adoption. Clients can also provide clear requirements for facilities management (FM) information to be handed over at project completion more easily with BIM. BIM is equally applicable to support facilities and asset management as it is to design and construc-tion. Indeed, the output of the design model may well replace the need for traditional operational and maintenance manuals. Being able to interrogate an intelligent model, as opposed to searching through outdated manuals, perhaps linked to interactive guidance on the repair and / or maintenance process, has obvious advantages.
The principal difference between BIM and 2D CAD is that the latter describes a building by independent 2D views such as plans, sections and elevations. Editing one of these views requires that all other views must be checked and updated, an error-prone process that is one of the major causes of poor documentation. In addition, data contained in 2D drawings are graphical entities only, such as lines, arcs and circles, in contrast to the intelligent contextual semantic of BIM models, where objects are defined in terms of building elements and systems such as spaces, walls, beams and columns. A BIM model carries all the information related to the building, including its physical and functional characteristics and project lifecycle information, as a series of ‘smart objects’. For example, a lift installation within a BIM would also contain data about its supplier, operation and maintenance procedures. This model can be used to demonstrate the entire building lifecycle and, as a result, quantities and shared properties of mate-rials can be readily extracted. Scopes of work can be easily isolated and defined. Systems, assemblies and sequences can be shown in a relative scale with the entire facility or group of facilities. Construction documents such as drawings, procurement details, regulatory processes and other specifica-tions can be easily interrelated.
In summary
A building information model can be used by the project manager for the following purposes:
• To generate 3D renderings in-house with little additional effort.
• To generate shop drawings for various building systems (for example, the metal ductwork in shop drawings can be quickly produced once the model is complete).
• For building control, planning and fire – these models can be used for review of building projects.
• Clash detection; because BIM models are created to scale in 3D space, all major systems can be visually checked for interferences. This process can verify that piping does not intersect with steel beams, ducts or walls and can graphically illustrate potential failures, leaks, evacuation plans, etc.
• Facilities managers can use BIM for renovations, space planning and maintenance operations.
• Estimating and quantification; BIM software has built-in cost-esti-mating features. Material quantities are automatically extracted and changed when any changes are made in the model.
• Construction programming; BIM is effective for creating materials ordering, fabrication and delivery schedules for all building components.
Project managers should also be aware of the potential risks of using BIM, namely:
• A legal risk to determine ownership of the BIM data and how to protect it through copyright and other laws. For example, if the owner is paying for the design, then the owner may feel entitled to ownership, but if team members are providing proprietary information for use on the project, this information needs to be protected as well. Thus, there is no simple answer to the question of data ownership; it requires a unique response to every project depending on the participants’ needs. The goal is to avoid reservations or disincentives that discourage partici-pants from fully realising the model’s potential.
• BIM licensing issues can arise. For example, equipment and material vendors offer designs associated with their products for the conveni-ence of the lead designer in the hope of inducing the designer to specify the vendor’s equipment. While this practice might be good for busi-ness, licensing issues can nevertheless arise if the vendor’s design was produced by a designer not licensed in the location of the project (Thompson and Miner, 2007).
• Control of data entry into the model and responsibility for any inac-curacies is another fraught area. Taking responsibility for updating BIM data and ensuring its accuracy entails a great deal of risk.
• Requests for complicated indemnities by BIM users and the offer of limited warranties and disclaimers of liability by designers will be essen-tial negotiation points that need to be resolved before BIM technology is fully utilised.
• The integrated concept of BIM blurs the level of responsibility so much that risk and liability will probably be enhanced. Consider the scenario where the owner of the building files suit over a perceived design error.
The architect, engineers and other contributors of the BIM process look to each other in an effort to try to determine who has responsibility for the matter raised. If disagreement ensues, the lead professional will not only be responsible as a matter of law to the claimant but may have dif-ficulty proving fault with others such as the engineers.
• Professional indemnity insurance and intellectual property rights protection.