See also "Peopleware", by de Marco and Lister, Ch. 9 - "Saving money on Space".

"[IBM researchers] watched programmers, engineers, quality control workers, and managers go about their normal activities. From their studies, they concluded that a minimum accommodation for the mix of poeple slated to occupy the new [Santa Teresa facility] would be the following:
• 100 square feed of dedicated space per worker
• 30 square feet of work surface per person
• Noise protection in the form of enclosed offices or six-foot high partitions[...]
The rational for building the new laboratory to respect these minimums was simple: People in the roles studied /needed/ the space and quiet to perform optimally. Cost reduction to provide workspace below the minimum would result in a loss of effectiveness that would more than offset the cost savings."

"In order to determine whether attitude toward noise level had any correlation to work, we divided our [Coding War Games study] sample into two parts, those who found the workplace acceptably quiet and those who didn't. Then we looked at the number of workers within each group who had completed the entire exercise without a single defect.

Workers who reported before the exercise that their workplace was acceptably quiet were /one-third more likely/ to deliver zero-defect work."

Actually, you should just find a copy and read the whole chapter^Wbook if you have not done so already.