1 bed 1 bath rent occupancy rules

Hi, I will be joining Clemson as a post Doc starting Nov. I was looking for 1 bed 1 bath apartments when the leasing agency told me about occupancy rules. I told them I will start my lease in Nov and my wife will be staying with me starting Jan 26. They said that in that case you can not have 1 bed apartment due to occupancy rules, rather I need to take a 2 bed apartment. Is there any rules like that across Clemson that only one person could stay in a 1 bed apartment?