Open plan was justified on collaboration. Remove the walls, the argument went, and people will talk to each other more.
The most widely cited study of the question found the reverse.
For a practical reference on the seven-minute payroll rule, Monitask provides this resource.
A note consistent with how this site works: figures below come from published research, and where a precise number is contested we say so. Check primary sources before quoting anything in a business case.
The central finding
The best-known work here is Bernstein and Turban's study of two organisations that moved from cubicles to open plan, using wearable sensors to measure actual face-to-face interaction rather than self-report.
Face-to-face interaction fell substantially — on the order of 70% — while electronic messaging rose.
The effect is not subtle and it is the opposite of the stated intent. People in an open room did not talk to each other more. They talked to each other less, and moved the conversation to a channel where it was less visible.
Why that happens
The mechanism is straightforward once stated.
Removing walls removes privacy, and people compensate. A conversation in an open room is audible to twenty people. So the conversation moves to a message, or to a booked room, or does not happen.
Interruption becomes cheap for the interrupter and expensive for everyone else. Anyone can approach anyone, which sounds like collaboration and functions as a tax on concentration.
Headphones become a wall. People rebuild the boundary with the tools available, and headphones are a worse boundary than a door because they also remove the incidental awareness open plan was supposed to create.
Visibility changes behaviour. People who can be seen at all times work differently, and generally more defensively — favouring visible activity over the kind that looks like sitting still.
What else the evidence suggests
Beyond the interaction finding, the broader literature on open plan is consistently unflattering:
Noise is the dominant complaint, and specifically intelligible speech — conversation you can make out words in is far more disruptive than louder undifferentiated noise.
Concentration work suffers most. Roles requiring sustained attention report the largest costs.
Satisfaction is lower with the physical environment across most studies.
Some findings on absence and health point in an unfavourable direction, though this is less settled.
Effects vary by role. Work that is genuinely collaborative and interruption-tolerant fares better. Work requiring concentration fares worse. Open plan applied uniformly optimises for one and penalises the other.
What it was actually for
Worth saying plainly, because the collaboration argument was rarely the real driver.
Open plan is cheaper per person. Substantially. More people fit in the same floor area, and reconfiguration is easier.
It is easier to supervise. Visibility was a feature.
It is more flexible. Teams can be reshaped without construction.
These are legitimate reasons. The problem is that they were presented as collaboration benefits, and the collaboration claim is the one the evidence contradicts. An organisation making a cost decision honestly is in a better position than one that made a cost decision and told its staff it was about serendipity — because the second version is checkable, and staff check it.
What the evidence supports doing
Not a return to individual offices for everyone, which is not affordable for most organisations and would not be the right answer anyway.
Variety, not uniformity. Different work needs different conditions. A floor that offers only one condition serves one kind of work.
Enclosed space for concentration, genuinely available. Not two phone booths for eighty people, which is what "we have quiet spaces" usually means in practice. If they are always occupied, they do not exist.
Acoustic treatment. The largest single improvement available to an existing open floor, and it is unglamorous enough to be underfunded.
Team-scale zones rather than one large room. Most of the benefit attributed to open plan is proximity to your own team, and most of the cost is proximity to everyone else's.
Norms, not just space. Whether it is acceptable to approach someone working, and how to signal unavailability, matters more than the furniture. This is free and almost never addressed.
The hybrid complication
Most of the open plan research predates widespread hybrid work, and hybrid changes the calculation in both directions.
Lower occupancy makes open plan less noisy and makes the concentration objection weaker on a Tuesday and stronger on a Wednesday.
But it raises the stakes on the days people do come in. If someone commutes specifically to collaborate and spends the day on video calls in an open room, the arrangement has produced cost with no benefit. See the office as a coordination device and video parity.
Desk booking changes the social geometry — proximity to your team, which was the main benefit, stops being reliable. See hot-desking and desk booking.
The honest position for a decision
If you are choosing a layout, the defensible version is:
Open plan is cheaper and more flexible. It reduces face-to-face interaction rather than increasing it, penalises concentration work, and its costs fall unevenly across roles. Those costs can be substantially mitigated with acoustic treatment, genuinely available enclosed space, team-scale zoning and explicit norms — none of which are free, and all of which are cheaper than the alternative.
That argument survives someone reading the research. The collaboration argument does not.
For broader public guidance and background, consult the National Institute for Occupational Safety and Health.