by Jess Sharman
A building information model is a digital description of an asset that incorporates every aspect of that asset – providing information on every element in order to make better decisions before, during and after construction. For the designer, BIM provides more than just a technological change in the way they work; it’s a complete refit of the entire design process.
Often mistakenly compared to when the industry moved from paper to CAD, moving from CAD to BIM is much, much more than that. Paper to CAD automated a process but left that process otherwise unchanged. With BIM, the traditional way of working is rendered obsolete and the process itself is completely transformed.
First we had tracing paper
At the heart of design we’ve long had 2D drawings (plans, sections and elevations) designed to principles agreed by all participants. Inefficiencies inherent in this approach include things like architect sketches differing from the plans or detailed drawings used by civil engineers. Similarly, architectural projections would focus on design layout while building construction plans showed what is above the ceiling and beneath the floor. The traditional process would see specialists working on separate drawings with tracing papers produced during co-ordination checkpoints to check for compatibility.
Then we had CAD
The need for more accurate computational and graphical design solutions saw CAD layers take the place of tracing papers. However, the interdisciplinary collisions remain, with meetings required to solve the conflicts. And while CAD made putting these conflicts right easier, the process was time consuming, and it was far too easy for the different kinds of plans to fall out of step as changes were made to architectural or structural details.
Supported by CAE
In parallel, computer aided engineering systems (both simple and complex) have been developed to support structure calculations under a plethora of different variants, with results feeding into CAD systems to adjust the model and produce structural drawings looking at dimensioning, reinforcement etc.
Now enters BIM
The BIM process uses a virtual 3D model of a proposed asset as the sole source of all of the information about that asset. At the heart of the process is an assigned, shared database that feeds a suite of complete project documents. Levels of BIM maturity determine what kind of digital information is created. Currently, industry leaders are at Level 2 and stretching towards Level 3, which will make construction management possible across the design lifecycle and dovetail with a range of standards and formats.
By using one, centralised data source that contains all relevant documentation covering architectural and landscape designs, construction and installation designs, bills of quantities and cost estimates reduces the possibility of errors and allows problems to be flagged earlier. Changes can be made more quickly and at less cost to the project.
Collision detection in BIM is much more exact than traditional methods. BIM systems take the standard data and highlight heavy (overlapping in space), light (free space and tolerances) and technological collisions (e.g., overlapping assembly and delivery schedules), ensuring significant cost savings during design and works stages.
New forms of designs offer greater advantages and flexibilities. 3D BIM is already seen as a natural extension of 2D design. 4D BIM adds scheduling to the mix. Elements are assigned in sequence of assembly, which offers new opportunities to divide projects into phases and visualise them with an accurate schedule of works to ensure products and materials are planned to arrive in time. 5D BIM adds estimation, making it easier to understand how the changes made in conceptual design impact on the bottom line. 6D BIM allows environmental protection and energy consumption information to be calculated, and 7D BIM incorporates facilities management information that will live and grow with the asset from first use through to decommissioning.
Arguably, BIM’s biggest benefit is the ability to analyse the concept designs to find those suitable for working up as structural designs. Manual examination and calculations have given way to models and concept designs under CAD, but under BIM we are provided with a far more efficient way of working. A 3D model prepared by an architect quickly evolves into an analytical model that can be used for structural analysis, with the architect able to keep up to speed on cost for each approved conceptual design.
Before embarking on a BIM implementation process, it is necessary to undertake a root and branch skills and capabilities audit to ensure your organisation has the kind of skills and roles in place to take advantage.
PAS1192 introduces the BIM Manager/Coordinator role. This role is as much about process and change management as it is about overseeing BIM deliverables. Key elements of the BIM Coordinator role include:
- A wider range of responsibilities than the Information Manager
- More closely associated with design (design lead)
- Responsible for BIM project set up: setting workflow goals and managing requirements
- Coordinating and maintaining the models: the process, the type of models, why they are created, how they fit together, ensuring models are interoperable and up to date
- Oversees clash detection ,quality audits, quantity takeoffs, and data conversion
A BIM Coordinator can serve as an Information Manager; however, an Information Manager is not a BIM Coordinator.
Employer Information Requirements (EIR)
The EIR provide advisory content and are part of the appointment and lender documents on any BIM project and define which models need to be produced at each project stage. They cover three areas: 1) technical – e.g., software, data exchange formats, level of detail, training; 2) management – standards, security, roles and responsibilities, collaboration, health & safety, and construction design processes, coordination and clash detection, delivery strategy, etc.; and, 3) commercial – e.g., data drop timing deliverables competence assessment.
Plain Language Questions clarify roles and responsibilities.
While whether certification actually means anything is a controversial topic, there are a few schemes in place that can help with ensuring compliance with BIM Level 2. This includes BRE Global’s BIM Level 2 Certificated Practitioner Scheme, RICS BIM Manager Certification, and NBS BIM Object Standard, which establishes the minimum requirements for BIM objects.
Any transition to new process, or even embarking on a speculative audit, can result in productivity dips impacting on business as usual, and there are a few things that you need to be aware of up front.
Hard and software are likely to be a key part of any BIM implementation budget. The collaborative nature of BIM working means that a multiplicity of licences and workstations may be needed according to individual need.
Education in new ways of working (both in terms of tools and process and the softer skills of team work) may be required but this can be expensive with payback deferred.
BIM is evolving and its terminology can be interchangeable depending on who you speak too – this can lead to misinterpretation and contradictions during a transitional phase. Similarly legal regulation around BIM based design is similarly in flux and playing catch up with the practicalities of new ways of working.
Determining how to attribute costs across all parties contributing to a BIM workflow can also be tricky. Who should bear the brunt – investor, designer or contractor?
In a BIM workflow, information gathering is front-loaded, potentially requiring a longer lead time. While some technical drawings can be prepared early, if these are not fully co-ordinated with the model you can mitigate the benefits and, indeed, run the same kind of risk as a more traditional CAD approach.
A couple of years ago, some of the earliest adopters offered Building.co.uk some key advice to share on getting started with BIM. This included:
- Understand that the biggest investment you’re going to make is not the software but the change management. BIM is going to transform the way you work as an individual and an organisation. The best way to benefit it to take a holistic approach, with fully integrated internal and external teams.
- Start by taking a look at where you are now and then determine where you want to be. BIM is about taking a collaborative, transparent approach, and championing that mind set can begin immediately.
- Make a plan. Recruit BIM champions throughout the organisation with varying levels of authority and have them communicate that plan across the business.
- Get leadership on board, so that people will listen. They don’t need to understand the technical details, but they do need to understand the process.
- Make the technology available to all. This allows everyone to place their focus on the process rather than the tools. Costs can be managed with some creative thinking. For instance, the consulting engineering group Ramboll buys a high spec PC whenever there is a new starter, no matter what that starter’s position. The new PC is then given to a power user, while that user’s old machine is passed down to someone else, and so on. This trickledown effect can see as many as four users provided with the spec’d rigs they need at the cost of one higher-end machine.
- Don’t wait to start a project. Teach yourself on your own time, and then find a willing client who will participate in a pilot project. Prepare yourself before you face that first, live BIM project.
- Approach BIM with a ‘business as usual’ attitude, and make it easy to adopt. Map already existing processes to complement a collaborative working style, address security concerns before they become an issue, and tailor company standards to support BIM processes.
Also key is training well but not training too early. Many of the early adopters learnt this the hard way. They invested in the software, had their people trained in it, and then went back to business as usual. When it came time to actually do their first BIM project, their people had forgotten most of what they’d learnt. So, invest in training, but time that training so that your people can go straight from it into a project
Also avoid the pitfall of focussing on software alone. Think instead about the wider BIM process. Isolated technical issues imposed by software can easily derail a project. Staff that are more broadly informed can see the bigger picture, meaning projects are less likely to stall.
Understand what BIM means for you
Just like the digital revolution changed the way we access films and music, BIM is changing the way we do projects. It isn’t just a new step in digitising an age-old process but a completely new way of working. Because of this, adopting BIM is about far more than hardware and software investment. You can’t just assign a BIM guy and go on with business as usual. BIM must become your business as usual.
They key is understanding what BIM means for you – now and in the future – and then making a plan and working that plan.
It’s going to take a lot of work up front, but the end result is better design, better construction coordination, richer and more complete data, and all of the financial (and personal) rewards that go with that.