Until they get the super-spread mechanics down, no one knows how much ventilation you need. The known lower bound is plausibly into "continuous sound of a train" air motion range, upward, and it won't necessarily be possible to refit into existing structures, which aren't designed with the necessary ventilation duct area, windows that open, and so on.

Plus common areas; the correct epidemiological answer is "you get your washroom". That's not going to fly in the current business climate.

So I don't expect any refitting; I do expect a lot of "return or be fired". And for this to go very badly indeed.