BIM is not Revit

D3-Hub is a BIM and data-driven design consultancy based in Bulgaria, working with studios and firms across Europe. This is the first in a short series that explains BIM in plain language for studios that are not using it yet.

Most studios that reach us for the first time open with a version of the same sentence. A client, or a public tender, has asked them to deliver in BIM, and they want to know which Revit license to buy. It usually sounds close to this:

"A client asked whether we work in BIM. I looked into it and it seems you need Revit. Which license should a studio like ours buy? We are five people. We would like to start modelling straight away, and pick up the rest as we go, the way we always have."

The question is fair. But it is also the wrong one, and it is the one almost everyone who comes to BIM starts with.

Why, after more than twenty years of BIM, is the BIM-equals-Revit link still so strong?

For years the message from the software industry was that BIM and Revit were the same thing. The two words were used as if they were interchangeable, and a whole generation of studios learned them that way. So the confusion is understandable. If you have spent twenty-five years in AutoCAD without ever delivering late, thinking of BIM as one more drawing program to learn on the job is the natural next step.

The problem is that it points you at the wrong first move. Buying the license feels like ninety per cent of the job. In reality, buying software is closer to the last ten.

So what is BIM?

BIM is a method before it is a program. Revit is one of the tools that work inside that method, and it is a capable one, but the part that matters is the method.

Here is the difference in a single object. In CAD, two parallel lines are a wall, by convention. You read them as a wall because you know the convention. In a BIM model you place a wall that carries what a real wall carries: its layers, its materials, its parameters. Put plainly, instead of drawing a picture of a wall, you place the wall itself.

That is the whole change, in one line. The geometry is only half of it. The other half is the information that travels with the model, and it is what the I in BIM stands for. Once the model holds that information it stops being only a drawing you look at and becomes something you can question: pull quantities while you model, watch costs by macro-group, check whether a junction between a slab and a wall will actually work before the site even opens.

None of that comes from the license. As we tend to put it on that first call: the license is the thing you buy once and forget. The method is the thing you build.

The cost of BIM, honestly

There is a cost, and it is only fair to name it. On a first project, starting from scratch, about a third of the time on the model is not modelling at all. It goes into wall types, families, naming, the shared conventions that a standard such as ISO 19650 asks for. After that groundwork, the work that used to eat days, confirming that every window and door is consistent across every sheet, becomes close to automatic. The cost does not vanish. It moves to the front, where it feels frightening, when it should read as a sign the work will go well. Think of making a pizza: you worry about the ingredients first, the oven is the last step. But if the right ingredients are not on the counter, cut the right way, if you do not know what to put on before what, so the moisture of one does not leave another soggy, the pizza will not turn out good.

What BIM means for a small studio

On a public project above a certain size, BIM is not optional, and it is not only your problem. It binds every discipline on the job: structural, mechanical, electrical, all of them. That is why a shared method exists at all. The naming and the conventions, and behind them a set of documents you may not have met yet, the information the client requires and the plan you write in answer, are there so that every model speaks one language.

You do not need to master all of that before your first wall. But you should know it is there, because "buy Revit and start drawing" quietly steps over it, and once you are past the first stage, going back to align everything to the standards becomes complicated and costs you twice the time.

The useful thing to understand for a five-person studio is small: the license is a purchase, BIM is a decision about how you work. Pick a project of medium size, usually the so-called "pilot project", and turning on consultancy support while you learn is a decision worth making. On a small job starting from zero, BIM is often more of a hindrance, and an honest advisor will tell you so. Then, once you have understood all the dynamics and learned the software, even the small project will benefit, and you will not go back to CAD.