it really depends on how much furniture you want to add how you want to arrange the furniture

A full bed is 53" wide..if you place them side by side with a nightstand in between..add to the width of that plus I would say two more nightstands (one on each side). On average, that would bring you to 17ft wide room. The length again, depends on what you want to use..the bed is usually 75" long

My mom did that. Measure for the 2 beds + nightstand between them, then allow 18- 24" minimum on the outside of the beds to navigate around while making them up. what else do you want; dresser, chest of drawers, chair???