To BIM, or not to BIM? That is the Question!


2019 has arrived, and the Irish Government BIM Mandate is due to start this year, with BIM required on complex public sector projects. spoke to Ralph Montague, Managing Partner of ArcDox, one of Ireland’s leading BIM consultancy practices, about how industry should decide whether they need BIM or not. 

What’s the big advantage or benefit of BIM?

If people are going to make an important decision on whether to use BIM or not, they first need to understand the advantages of benefits that BIM may bring, and also the challenges.

When you describe a building, or elements of a building, using traditional 2D drafting methods, you have to separately produce multiple pieces of information or documents (plans, elevations, sections, details, schedules, specifications, bills of quantities etc.) to paint the full picture. The designer, or technician, is focused on the individual output documents. If you need to make a change, or update, you have to amend all these multiple documents to reflect the change. You also have to check, and cross-check, that all these documents are coordinated and describe the same thing, otherwise, there may be confusion, which could lead to delays, abortive work, or rework, cost overruns, variations or disputes, and possibly even litigation. 2D documents are typically shared or “exchanged” as printed documents, or static files (PDFs), that can’t be used by others.

When you describe a building, or elements of a building, using 3D BIM (Building Information Modelling), you place a 3D BIM “object” into a “virtual building” model, that represents the real or physical component – in other words, you’re assembling or constructing a “digital twin”. The 3D “object” contains the graphical information (size, shape, location, connections etc.) and non-graphical attribute information (properties), that is used to generate any output documents (drawings, notes, schedules, etc.). The designer, or technician, is focused on building the model, and the model generates the individual output documents. If you need to make a change, or update, you simply make the change once, in the model, and you can automatically regenerate all output documents. You don’t have to check, or cross-check, the output documents, as they are automatically coordinated, because they are being generated from the same model. 3D BIM can be shared or exchanged as digital data files that can be used by others.

Since people can look around the 3D model, they have a much greater understanding of the building, which leads to less confusion, fewer delays, reduced abortive work and re-work, fewer cost overruns, variations and hopefully disputes. Also, since in BIM you effectively have a digital database of information that can be shared in an electronic format, you can do things that were never possible in the 2D environment, like 3D Coordination (clash detection), 4D Sequencing (time, logistics, safety), 5D Quantity Extraction (cost control), 6D Analysis (structure and energy performance), and 7D Asset Management (capturing facilities and lifecycle data).

So BIM leads to a better understanding of the Scope (3D), Time (4D), Cost (5D), and through analysis (6D) better understanding of performance and Quality, and results in a digital, searchable, accessible, accurate database of design, construction and asset information (7D). BIM is better – better buildings, built quicker and built cheaper.

Why wouldn’t you use BIM? Clearly, working in BIM is a better and more efficient way of producing and managing information about buildings, and brings many advantages or benefits over traditional 2D drafting. So why would people want to continue to use traditional 2D drafting methods?

One reason may be that BIM is a different method of working, and requires people to learn something new. People don’t generally like “change” at the best of times. Also, working in BIM may require some financial investment into new hardware, software, training, and time investment into learning new skills.

Another reason may be that 2D drafting methods use techniques of “abstraction”, where the building isn’t being fully described, but only partially described, on the assumption that, with a limited amount of information, a competent builder will be able to construct the building (i.e. work it out on site). Whereas in BIM (in 3D anyway), you may need to more fully work out and describe the “virtual building” than you would previously have done in 2D (i.e. you can’t “fudge” stuff in 3D BIM, the way you can in 2D). Of course, we all know that “working stuff out on site” is a very expensive way of doing things, and the statistics that over 70% of projects end up over budget, or delayed, or both, would prove that this way of working is fundamentally flawed. So while BIM may be more efficient in the long run, it may require more work up-front, to resolve and coordinate the design more fully, before going to site. Traditional fee structures, based on 2D drafting methodologies and high levels of “abstraction”, may be a challenge to working in BIM.

Another reason may be the “fragmentation” of responsibility across design and construction, where designers are only required to communicate “design intent” information, and contractors are required to produce detailed construction/fragmentation information. Designers may feel that by doing more work up-front in BIM, than they would previously have done in 2D, that they are creating benefit for others, but not being rewarded accordingly. Although there is a debate about whether designers were simply getting away with poor levels of information previously in 2D, which is now being “exposed” by 3D and digital information exchanges.

We all know that delaying the production of detailed construction/fabrication information to very late stages in the build process has been one of the biggest contributors of “waste” (confusion, delays, abortive work, or rework, cost overruns, variations or disputes). The earlier you can get input from specialist contractors, the better, and the exchange of design intent information in digital 3D model format, that allows contractors and specialists to quickly and easily assess and analyse “constructability”, compared to exchanging static 2D information in formats that require contractors to start from scratch, is obviously a big advantage of BIM.

And finally, to add to the confusion, we have people who practice “pseudo-BIM”, where they carry out initial design work in 2D, and attempt to convert that to 3D BIM at a later stage, effectively doing the work twice, and introducing possible “conflicts” between 2D and 3D information. Clearly, this is not very efficient, and ends up diluting the benefits of BIM.

What is the answer? It seems obvious that BIM is clearly the way to go, because of all the advantages and benefits, but as you say, there are challenges to overcome when confronting traditional methodologies of working, and current skillsets in the market. How do we get over these?

You’ve heard of the “Golden Rule” – “They who have the Gold make the Rules!” One of the easiest ways of overcoming these challenges, is simply for employers or clients (those who are paying for the services), to request, require, or demand, the proper use of BIM from all parties from the very beginning of a project, ensuring that information is created, managed and exchanged in the most efficient way possible, and that “exchanges” of information, are shared in digital 3D model format, that allow subsequent parties to use information, rather than making people recreate the same information over and over again. Once everyone understands that this is what is required, then everyone can tailor their services, fees and timescales accordingly.

There is a fear, on behalf of clients, that asking for BIM will cost more money, or take more time (a myth often perpetuated by professional advisors). But that is not true. Using BIM properly is a more efficient way of working, and therefore takes less time, or costs less overall. But if your team have to acquire new skills, there may be some additional time involved, and there may be a little more up-front work to get the model right, before going to site. You may need your designers to go beyond high levels of 2D “abstractions” and schematics, to resolve and coordinate design properly. You may also want to engage specialist contractors earlier (rather than later), to get the best results. You get what you ask for, and you’re unlikely to get what you don’t ask for.

Clients who don’t ask for BIM, or who say “we may look at BIM later” are simply fuelling, or perpetuating, traditional 2D and “pseudo-BIM” practices, and should expect to get the traditional results on their projects (the usual delays, variations, cost overruns, disputes, poor quality, etc.). 

The Irish Government is a client or employer that is now starting to ask for BIM. What should the industry expect from the BIM Mandate this year? 

The Government has said it will require BIM Level 2 on complex projects from 2019, with medium and simple projects being phased in over the coming years. BIM Level 2 maturity means that all suppliers (designers, contractors, specialists, product manufacturers, etc.) who produce information, need to do that in BIM, and follow the standard PAS1192-2 “Specification for Information Management for Capital Delivery of Projects using BIM” (PAS1192-2 will be replaced by ISO19650 later in 2019, once an Irish national annex has been agreed by NSAI).

Out of the above, the following flows:

  • An Employer’s Information Requirement (EIR) must be provided (Section 5 of PAS1192-2).
  • Every party will be asked to sign up to a BIM Protocol (a legal addendum to their appointment or contract, setting out rights, responsibilities, liabilities and exclusions of liability etc.), which includes a responsibility matrix or Model Production Delivery Table (MPDT).
  • The lead designer, and the main contractor, will be asked to take on the role of Project Information Manager for design and construction stages respectively.
  • At tender stage (for both design and construction services) a pre-contract BIM Execution Plan (BEP) needs to be produced by suppliers/providers, in response to the EIR, along with a Project Implementation Plan (PIP), and BIM Capability Assessments (Section 6 of PAS1192-2).
  • Once appointed, a post-contract BIM Execution Plan (BEP) needs to be produced, in response to the EIR, including the Master Information Delivery Plan (MIDP) (Section 7 of PAS1192-2).
  • An information repository or Common Data Environment (CDE) needs to be established, following BS1192 file naming convention, and approval workflows (Section 9.2 & 9.3 of PAS1192-2).
  • A Digital Plan of Work (DPoW) needs to be put in place, clearly defining the Level of Model Definition, being a combination of Level of graphical Detail (LOD) and Level of non-graphical data or attribute Information (LOI), and assigning responsibilities (Section 9.8 & 9.9 of PAS1192-2).
  • A common classification system (Uniclass) must be used by all for organising models, documents, project information, cost information and specifications (Section 9.10 of PAS1192-2). 

All of the above may be new terminology, but in reality, it is simply “good practice” for project and information management. My recommendation to any private sector clients, who want to use BIM, is to use and follow the same industry tested standards, and not to make up their own ways of doing things, which will just create more confusion. The question “to BIM, or not to BIM?” will now be irrelevant for complex public sector projects in Ireland from this year, and eventually for all public sector projects over the coming years. Many clients in the private sector have also already answered that question. Industry, or the supply chain, now simply need to get up to speed to deliver. As the saying goes “Go digital, or go home!”

Follow on LinkedIn and on Twitter @BIMIreland #BIMIreland #BIMPeople

Comments are closed.