5D BIM: What skills does a 5D QS need?

There are various definitions of what 5D actually is. To me 5D is simply when I estimate from a model.

In terms of where 5D first got defined, it’s in the US, and there it’s referred to as “quantity take-off”, which I believe drastically understates the exercise. If it was just about taking off quantity then we don’t know the cost of a project until the model is complete – and that’s just too late. The other issue is that the estimator doesn’t sit at the same table as the designer and the owner and the process is not transparent, which means there is no trust built within it.


5D Skills

Pulling Information

I believe a much better alternative approach is for a 5D QS (or an estimator or whatever you want to call them) to pull information from a model at the time that he needs it and then push back data at the right time for the design team and the owners to be able to receive that information.


It doesn’t matter if it’s an architectural model or a structural model or a civil model that this information is being pulled from. Most pieces of software can do this extremely well and this is a fairly basic skills. The excuse of “It’s not classified correctly” or “It’s not in the way that I want to see it” isn’t valid. You need to be able to get information from whatever format that it is in.


Improve the Information

The next step is to improve this information. At Mitchell Brandtman we use an Australian based software called CostX, among other platforms. We add parameters into the file that allows us to filter information in a different way. Again, this isn’t very difficult to do but what is really difficult to do is to figure out exactly what parameters you really need. And that comes down to mapping…



Mapping, in short, is a collection of formulas that allows us to replace measuring with calculating which formulas we need to use to filter information in different ways and what filters we need to put in place to be able to make that work. We measure elementally and we don’t measure by trade which makes the process more effective. When we map, we map the quantity and map the description. So, while there may not be a description in the model that says this is an XYZ, we take different pieces from different places and assemble it right to get the right description.


It may not be what you’re used to seeing in a standard method bill but it is enough to get what your intent is across the line.


Applying the Skills

The technology is here, it’s reliable, and it’s very easy to teach as well as learn. But the technology alone won’t create the certainty that is needed. That comes down to knowledge of using intelligence and wisdom to leverage the technology to produce far better results.


From my mind this isn’t a threat to estimators or quantity surveyors – it is an incredible enhancement tool.


Creating Cost Certainty, Transparency and Trust

This is only a snapshot of some of the skills that a 5D QS needs. However, a combined use of these skills enables you to set up an estimating system that gets constantly rerun so we end up with a notion of real time feedback on what costs are doing as design changes as well as many other benefits of that. I believe it starts to create better buildings because you can target money at the most important design features – money isn’t tucked away in a concept where people are not aware of what something is going to cost.


A process like that means the efficiency of a design can be tested in the very early phases before the models have started – and it’s at this point where we have the best opportunity to influence costs. Whereas once a project is fully designed this is very difficult to do.


When you have transparency and clarity about where money is, it creates trust. Trust is what we need on construction projects to collaborate in the way we need to for a project to be a success. Money is the key to project trust, so the more we talk about money the more we can move into a truly collaborative space.


David Mitchell is a 5D Quantity Surveyor and Partner of Mitchell Brandtman. With 30 years of industry experience and a family background in construction consulting, David has a deep understanding of construction and development. David is passionate about people, open leadership, technology and the collective ability to create and shape opportunities for positive industry change.  He develops and implements project and enterprise cost strategies, consults on disputes, and shares knowledge through teaching and conducting quarterly cost research.


He regularly contributes to Mitchell Brandtman’s construction blog www.mitbrand.com/blog where you can read more of his views on BIM, Lean Construction and 5D Cost Planning as well as the views of many other authors. 

For more on 5D and BIM advocacy please visit Mitchell Brandtman’s website www.mitbrand.com


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