Do you have a large, imposing circulation desk?
These kinds of desks not only take up a lot of space, but they serve as a physical and psychological barrier between staff and patrons. Service desks are trending much smaller and less monumental, making it easier for staff to come out from behind it and help patrons on the floor.
Here are two smaller service desks -- the left is in Edgartown, MA and the right is in Dayton, OH. Note the "Ask Me" flags next to the Dayton example.
This desk is more traditional in configuration, but it is shorter, is open at the sides, and it's not anchored to the floor, so it can be moved as needed.
It also has three sections with tops that can be raised or lowered to the desired height -- great for ADA and staff ergonomics.
Traditional stacks take up a lot of space. Consider replacing traditional shelving with mobile units, making it possible to move them out of the way and use that space for other activities.