Open Carry at Work

Okay, so I was having a conversation with the maintenance worker where I live. He was interested in getting a CCWL and we were talking about where you can carry and WORK came up. I had told him that you can open carry at your place of employment. The question I have is,

Since he is employed by the apartment complex as a maintenance worker, can he open carry while anywhere on the apartment complex since that is his place of employment.