"These new guidelines provide a common framework to unify the division and help us address the industry-wide questions and concerns raised around the practicalities of investment banking," the memo said.
The letter was signed by John Miller, head of Americas investment banking; Joe McGrath, co-head of global finance and risk solutions; and Paul Parker, chairman and head of global mergers and acquisitions.
"It seems like management has their heart in the right place, but time will tell how these new measures impact the quality of life for junior bankers," said a current Barclays employee familiar with the investment banking program.
"There is an entrepreneurial element to being a successful analyst or associate, so no level of structured 'protection' will keep everyone out of the office; investment banking continues to be a competitive industry despite the recent image challenges," the person added. "The challenge around these lifestyle initiatives for all banks going forward is how to make them an accepted part of the culture. Paradigm shift? We'll see."
A Barclays spokesman declined to comment.
—By CNBC's Lawrence Delevingne. Follow him on Twitter @ldelevingne.