There is a trick, well-known in consulting, which goes roughly like this. You walk into a hotel. You ask how much they pay the doorman. They give you a number. You explain that the doorman’s function is, definitionally, to open the door. You show them an automatic door-opening mechanism which will do that job for considerably less. You claim the saving. You walk away. And five years later, when the rack rate has fallen, when vagrants are asleep in the entrance, when the regulars have quietly moved to the hotel down the street, none of that falls to you. That falls to somebody else. The person who suggested replacing the doorman is long gone, probably doing the same trick somewhere else.
Rory Sutherland calls this the Doorman Fallacy. The trick depends entirely on defining the role by its most visible, most easily automated function — and then pretending that nothing else was going on. The doorman doesn’t just open the door. They hail taxis. They recognise regulars. They project a certain quality of welcome that no automatic mechanism has yet found a way to quantify. None of that appears on the cost-reduction spreadsheet, because none of it was on the job description. And so none of it counts when the saving is claimed. The saving is clean; the destruction is messy, diffuse, and someone else’s problem.
You will have met this trick. You may not have recognised it at the time.
In architecture and BIM, the doorman has a different job title. They go by BIM Manager, or BIM Lead, or sometimes just “the technical one” — the person who fields the question nobody else knew they needed to ask. Their job description says something about model management, standards, and coordination. What it doesn’t say, because it can’t quite be written down without sounding unmeasurably vague, is that they are the load-bearing element between design intent and construction reality. They are the person who noticed, three weeks before issue, that the structural grid and the facade module were in polite but irreconcilable disagreement. They are the person the contractor calls at half seven on a Tuesday morning not because the BEP requires it but because they know they’ll get a straight answer. They are, in the most literal sense, the one who absorbs the coordination debt before it becomes a claims dispute.
All of that is invisible on a cost model. Which is exactly why it’s so easy to remove.
The pressure to do so has intensified significantly. AI tools, automation pipelines, and the general narrative that coordination is now a software problem rather than a human one have given the people who run these exercises a new and more sophisticated vocabulary. Instead of replacing the doorman with a door mechanism, they are replacing the BIM Manager with a platform, a dashboard, and a set of automated clash checks. The saving is identified. The headcount is reduced. The case is made. And the people who make the case are, by and large, not going to be the ones unpicking a late-stage coordination failure on a contract where liability is live and the model was generated at speed by a team that didn’t quite understand what it was producing.
The Doorman Fallacy works because of a structural asymmetry in how businesses account for decisions. Cost reduction is immediate, attributable, and promotable. Value destruction is slow, diffuse, and almost impossible to pin to a specific earlier decision. The consultancy that claimed the saving from removing the doorman does not appear on the hotel’s P&L four years later when occupancy has declined. The executive who justified it has moved on, or reframed the context, or found a different variable to attribute the decline to. The asymmetry isn’t accidental. It’s the architecture of the incentive.
This is not a new observation. What is new is the speed at which the mechanism is now being applied to technical roles in architecture, and the sophistication of the language used to dress it up. “Leaner delivery models.” “AI-augmented coordination.” “Right-sized BIM.” Each of these phrases performs the same maneuver: it defines the role by its most countable, most reducible function, prices the reduction, and sidesteps the question of what else was happening while the headcount was present.
There is a version of this story that ends with a prescription. A clear set of steps that BIM Managers can take to protect their position, demonstrate their value, and survive the efficiency exercise. That version is not this piece.
What this piece is saying is simpler and less comfortable: the Doorman Fallacy is a structural feature of how architectural businesses — and most businesses — account for decisions. It is not a mistake made by bad actors. It is the rational behaviour of people whose incentives reward cost identification and do not penalise value destruction. Understanding that is more useful than resisting it, because resistance aimed at the wrong target is wasted effort. The consultant who runs the exercise is not the problem. The accounting structure that makes the exercise possible — that separates the moment of saving from the moment of consequence, and assigns them to different people — is the problem.
Until BIM management is priced, scoped, and held accountable in the same contracts that currently reward its removal, the doorman will keep getting replaced. Not because anyone decided he wasn’t valuable. But because nobody wrote down what he actually did.
And automatic doors are so much easier to put on a spreadsheet.