26 May 2016

How Usable are BIM Standards?

This month the UK Chartered Institute of Building (CIOB) published an article in their BIM+ blog.
it is a series of interviews with people involved in having to use BIM.

It is a timely and interesting article, and as regular readers of my blog will appreciate, close to my heart. A sample:
“People like me are invited on seminars and conferences and sent papers on BIM, but the information isn't easy to navigate,” he says. “It is made to sound more complicated than it really is and I'm having difficulty understanding what it is I have to do that I am not already doing."
Equally interesting are the comments on a LinkedIn group discussion about the article. Many thought those complaining about BIM standards simply didn't get BIM, and furthermore don't want to. Discussion on whether the contents of current BIM standards are good or bad seems to be not only avoided, but shut down.

Do I think BIM standards are unnecessarily complex? You bet. I also believe they are inadequate.

What makes a good Standard?

It is not enough to just have a standard, to provide something for managers to tick off, they must also serve a purpose for those that use them.

At a basic level standards should:
  • create consistency.
  • reduce industry effort.
But these aims won't be met if no-one, or insufficient people, follow the standards. For standards to work they must:
  • be useful for the creators of information.
  • be useful for the users of information.
To work in the real world standards must be evolutionary, not revolutionary. Each consumer of a standard must find it useful to them. Just as each evolutionary change has to be useful for it to survive in a population and so be passed on.

At the moment in BIM standards only "create consistency" is being considered. A tick box for project initiators and managers. When it comes to individual standards there is little consideration of reducing effort, or assessing cost benefit. When the additional effort required to comply with a standard is questioned it is dismissed as immaterial when considered against the overall savings of using BIM.

The bottom line is that although you can try and force people to adopted standards, they will only actually be used if they are useful to those who have to follow them.

BIM Standard Inadequacies

Talk about BIM standards always revolves around the need to have them. Of course we need them. It is not worth discussing the point. What is more relevant is how adequate are they? Are up to doing what is expected of them?

I'm not an expert on standards, nor do I claim to have an intimate knowledge of all BIM standards. But when I do investigate particular BIM standards I always find inadequacies. I don't do enough of an in-depth investigation to find all deficiencies, but when you find one you start to wonder if there are more. Here are some examples.

PAS 1192-2

The underling principles of PAS1192-2 are probably OK, but it is hard to tell. It is so overly prescriptive with poor explanation of objectives.
The section at the beginning titled "Fundamental Principles" is completely opaque to anyone without pre-knowledge of BIM. The problem is it explains principles in terms of BIM processes, rather than construction and operation processes.
Although the section titled "Scope" is easier to follow, PAS1192-2 gives the impression it is about a totally new discipline rather than a more efficient way of doing things that are already being done.

I have other criticisms, see them in my post Procuring BIM - PAS 1192-2 and acif PTI


I have to say I don't understand COBie.
Why require an email address for a product rather than a URL?
Why insist "N/A" be against all fields where there is no data without distinguishing whether the data is not applicable, not available, or not known yet?
I could go on. Read more in my post to COBie or not to COBie

But I've kind of given up on COBie. I'm not a facilities manager, I don't know how they work or think. If they find COBie inadequate for their purposes they should speak up.

But there is another issue with the use COBie that impacts on standard compliance and implementation.
COBie is from the US. It was developed by Bill East for the US Military. It subsequently became a US standard (NBIMS). The UK government (under advice) decided to base FM data delivery on the COBie standard. The UK developed their own COBie template files and made them publicly available.

The problem is the UK Templates don't exactly follow the US COBie standard. There are some spelling differences (critically important if computers are going to be used for processing), and examples in the template that contradict the US COBie. I've seen questions like this a few times in LinkedIn discussions:
"Would someone be able to confirm whether the COBie UK 2012 standard follows the NBIMS V3 and exclude certain Ifc types, such as Walls and Slabs? BS1192;4 (Fulfilling employers information exchange requirements using COBie) refer to FM Handover MVD and NBIMS V3 so should exclude these items, however the UK COBie example includes them, are they wrong?"
The original US COBie specifically excludes a building's fabric like walls and floors because they are not a "managed asset". The (sensible) basis of this is that is facility management don't have a remit to alter walls and floors so why include them in their data? (surface treatments to walls, which may come under their remit, are treated differently in COBie).

Now it could be a mistake. An overzealous, inexperienced minion added walls to the example template. But whenever this issue comes up it is vigorously defended on the basis that a facility manager "might" want to include walls. Under that logic COBie could include absolutely everything in the construction model. Which kind defeats the purpose of having a standard.
For more on how the UK is misunderstanding COBie see my post COBie is not what you think it is

NBS National BIM Object Standard

Where do I start. Every time I re-read this "award winning" standard I am in awe of how unhelpful it is.
I make a lot of BIM components. My last job was creating components for a pre-fabrication system. Yet there is nothing in the NBS National BIM Object Standard that I find useful, that would help me standardize the components I make.

It contains methods that can not be done in the most popular BIM software.
The standard insists it own parameter names be used, so instead of Revit's built in parameter 'Fire Rating' the name 'FireRating' must be used. The standard suggests mapping 'Fire Rating' to a new custom parameter  'FireRating' .
But you can't.
Firstly you can't create formulas for wall parameters in Revit (because they are not a loadable component), secondly it is not possible to use text parameters in formulas. Now these may be deficiencies of Revit, but the fact remains anyone using Revit can not follow the NBS standard. Why produce a standard most people can not comply with? Is it arrogance or ignorance?

The NBS don't even follow the standard when naming components in their own BIM Object Library  (see how in my post NBS BIM Object Standard - Where is the Impact Statement?).

Of course the reason they are not following their own standard's naming convention is because it hinders efficiency. But they refuse to change the standard because the naming convention comes from another standard - BS 8541:1 Clause 4.3.2.
To see how the NBS try and justify their approach have a look at this LinkedIn discussion.

Which is a fundamental problem with the current approach to standards. Rather than directly addressing the problem at hand (in this case one of naming) the "correct" approach is to always refer to another standard. It is one of the reasons standards are filled with references to other standards, making them incomprehensible to normal reading. Whilst there may be good reasons to refer to another standard rather then re-invent the wheel, it seems to be happening with no assessment of whether the referred standard is appropriate. Find a standard with a similar purpose (e.g. way of naming files) and then use it without question.


Before BIM there existed building classification systems. In the US Omniclass was created by combining a number of related classification systems (Uniform, MasterSpec etc). In the UK Uniclass was developed. These systems were mainly used by specification writers and estimators.
When BIM came along they seemed like a good way to classify objects in a BIM model. Autodesk added the ability to add classification numbers and descriptions to Revit objects. They also created data files of Omniclass values. But what they found is the existing classification system was not deep enough to be able to give every object that may be used in a Revit model a unique number. They had to add an extra 3 levels of numbers.

So what everyone in the industry assumed was a way of uniquely identifying every element in a building project actually couldn't.

This is an example of what I call the 'Delusion of Standards'. The delusion that a standard does what the authors and promoters think it can. And they maintain this delusion by not testing the standard in the real world, and shutting down any criticism. After all, it is less effort to convince people something is true than to produce evidence that it is true.

In the UK they realised the original Uniclass was inadequate for BIM use. Mainly because of the overall structure and lack of consistent structure between tables. To their credit they are revising it, creating a new Uniclass2 (now called Uniclass2015, I think, I haven't checked lately).
The emphasis is on 'revising' - it is not complete. This is another issue we in the industry have to cope with. Being told to comply with standards that are incomplete.

For more background on classification systems read my post Classification - not so Easy


IFC is at the core of BIM standards. Fundamentally it is a way of structuring digital data that describes buildings. Specifically data for computer programming. It was never intended for building professionals to use directly (if you think it is have a look at this example).

However the IFC structure (or 'schema' as it is called) can be used to structure data us mere mortals interact with. COBie is an attempt at this. The usual COBie deliverable is a spreadsheet file. The data is structured to follow the IFC schema and uses IFC names for things. It is touted as "human readable", but is only just. If directed and instructed adequately anyone can fill in the data, but it requires someone with deep knowledge of IFC to do the instructing.

So whereas IFC is fine for structuring computerized BIM processes it is not suitable for humans. Unless you are a computer programmer requests to "comply with IFC" are a nonsense. The most we can due is use software that claims to be IFC compliant.

Where most of us interact with IFC is with IFC files. That is BIM files in an IFC format (there is more than one). This is promoted as an "open format" that "any software can export and import".
Not because IFC can be exported and imported by all softwares successfully, but because that is the aim of IFC, or specifically buildingSMART, the not for profit and mostly volunteer organisation that promotes IFC.

It is a funny situation. A standard is created, and when particular softwares don't interact with that standard particularly well it is always the software's fault. On the one hand we have softwares actively being used by thousands (millions?) of people to do real world things, and on the other we have a standard artificially created to do theoretical things (there are no authoring softwares that natively use the IFC format). I don't understand why IFC is so sacrosanct.
For more on IFC refer to my post IFC, What is it good for?

But there is another issue with IFC that is not widely known. It is incomplete.

Last year I was upgrading my door library and I thought I would make them IFC friendly. That is, ensure they have enough parameters to support a compliant IFC export.
After some searching I found where buildingSMART keep their IFC specifications. First problem there are two versions, IFC 2x3 and IFC 4. The latter is the most current but not widely supported. Yet. Even though it has been out since March 2013. I decided to go with IFC 4.
I found some parameters (called "properties" in IFC) to do with doors. Mostly concerning geometry, which Revit already has native parameters for. But I couldn't find anything to do with door hardware (locks, latches, hinges etc.).

I though this can't be right. Nearly all buildings have doors, and all doors have hardware. So I asked the LinkedIn IFC group.
What surprised me was the attitude, the immediate assumption that IFC was faultless. Irrelevant other standards were suggested, and helpful suggestions that I develop my own IFC door hardware dataset. Someone offered the list of parameters NBS created for their BIM Object Library as a 'standard'.
But how can it be a standard if different groups create their "own IFC fields" as one commenter suggested?

So no, there are no IFC definitions for door hardware (or window hardware for that matter).
Which means it is not possible to use IFC to issue a standardized construction door schedule.

Do we bother with standards?

BIM standards do not make a pretty picture. Certainly not the utopia BIM Evangelists promote.

To be fair most are still being developed, and predominately by unpaid volunteers and inexperienced academics. The standards are young and untested.
The problem is they are being treated like some kind of dogma that can not be questioned. That the basis for assessment is wholly within the world of standard creation and other standards, not the real world of construction and facilities management where real things happen.

But standards are fundamentally a good idea. The computer industry heavily relies on standards, we wouldn't have all our e-devices without robust standards.

The solution is not in how we rid ourselves of these troublesome standards, but in how we make them useful.

For my two cents I see two fundamental problems.

Lack of Clear Objectives

High level standards like PAS 1192-2 seem to assume they must be as prescriptive as a standard for door hardware (for example, if such a thing existed). They don't, different processes can achieve the same results. For example you don't HAVE to use IPD contracts to get digital FM data.

High level standards should follow a similar format as the Building Code of Australia (and many other standards):
  • Objectives 
  • Criteria to meet objectives 
  • Requirements that are deemed to satisfy 
This structure means that if the objectives are demonstratively achievable any process can be used, but still provides prescriptive processes for the unimaginative.

As long as Objectives are be based on real world outcomes, not objectives wholly internal or in reference to other standards, like this from PAS1192-2 Fundamental Principles:
"application of the processes and procedures
outlined in the documents and standards indicated
in Table 1; "

Lack of basic information standardization

The second is that there is not enough work being done on low level standardization. Like IFC properties for door hardware.

Manufacturers data needs to be consistent, so different manufacturers provide the same data for the same products. It would also be helpful if construction data like door schedules were standardized across all projects.

It seems perverse that we have highly prescriptive standards on processes that manage non-standardized data. An elaborate mechanism to ensure the delivery of door data where this is no standard to say how that door data is to be structured.

Admittedly there is work being done in this area, but not nearly enough, and not fast enough. The UK government would have got more bang for their buck (pop for their pound) if they focused on funding and enforcing standardizing manufacturer data rather than untested theoretical BIM processes.

In fact it appears governments have to get involved looking at the failure of standardizing manufacturer data in the US. Bill East made this comment in a LinkedIn discussion:
We should, we need, to bother with standards. But we need to get them right.
In the meantime how do those of us on the ground, those having BIM standards thrust at us, deal with this unsatisfactory situation?

Don't worry about Standards

I'm not saying ignore BIM standards, just don't take them too seriously. Because BIM standards are not the most important thing you need to understand when utilizing BIM.

The most important thing you need to understand is how your BIM software works.
For designers like engineers, architects, sub-contractors your BIM authoring software, for contractors your BIM federating, estimating and scheduling softwares, for facility managers your BIM capable facility management software.

BIM may be a process but it is a process of managing software. If that software is used inefficiently or inaccurately it doesn't matter how good the management process is, the result will still be a disaster. The problem is not that people don't understand the BIM standards, it is that they don't know how to use BIM software properly.

There is no point a prospective taxi driver learning the streets of the city if they don't know how to drive a car. For managers, knowing the best places to distribute your taxi drivers around the city won't bring work in if none of them know how to drive.

Learn the Software, not the Standards

Unlike standards BIM software is made in a competitive market where the customer matters.
Unlike standards if their product is not useful they will do something about it (if only to the degree that it out-competes the competition).

Good quality BIM software (not CAD with a BIM add on) is designed to do the things you do. Unlike CAD which is for generic drawing BIM softwares are designed for specific disciplines. You will be surprised at how many of your processes are already built into the software. For example Revit has methods for doing area plans, sun studies, energy analysis, managing revisions, managing cross referencing, and many others. ArchiCAD has similar functionality.

But you have to use BIM software the way it is designed to be used. You can not simply force it to mimic the way you have always done things.
A lot of smart people have put a lot of thought into BIM software work processes, a lot of other people are using them, and those processes are likely to be BIM standards compliant.

Use the introduction of BIM software to review existing practice, develop new processes and retrain staff. When I teach Revit I do more than just show how to use the software. I introduce new ways of doing things. More efficient, more accurate ways. Like changing door parameters (to keep the door analogy going) instead of working through a door schedule spreadsheet, colour coding different door types, like fire doors; escape doors; disable access doors, so it is easy to check the right doors are in the right places.

BIM is, and should be, useful to everyone. Work out how to make BIM useful to you. How you can use your BIM software to make your processes more efficient, your output higher quality, to reduce your uncertainty and risks.

If you do that you don't need to comply with BIM standards, because you will be doing BIM.

When it comes to standards compare the work processes you have developed for your purposes against BIM standards, and see how they can be interpreted to match your needs. As I've shown above they are so full of holes it shouldn't be that hard. And even if your interpretation is not strictly legit it is unlikely there is anyone who can follow those standards well enough to realise.

So don't worry if BIM standards appear too complex, don't seem that useful. Forget about them. Concentrate on getting the most - for you, out of your BIM software. Once you do that everything else will fall in to place.