Are open-plan offices good for business?

There’s an interesting article in this month’s edition of Director, the IoD’s magazine, setting out the pros and cons of open-plan offices. I suspect that the ideal solution is a combination of both; i.e. open-plan working but with readily available breakout areas or offices for when some privacy or just peace and quiet is required. It would be interesting to hear if anyone has experience or evidence to support either the pro or con camp.