Forming and maintaining an overview of an information space is key to competent action in many situations and often supported by overview displays. We investigate the cost of the improved overview associated with the introduction of electronic whiteboards in four emergency departments (EDs). In such a dynamic environment the work that goes into keeping the whiteboard current is, we contend, an indicator of the cost of maintaining an overview. On the basis of log data for the period 2012–2014 we find that the ED clinicians make an average of 1.91 whiteboard changes per minute to keep the whiteboard current. Performing these changes takes an estimated 6647 h a year in each ED. While the whiteboard is well-like and has improved the clinicians’ overview, our cost-of-overview estimation shows that it consumes substantial staff resources. This reflects the value the clinicians assign to having an overview but also reveals the amount of resources removed from other activities to maintain this overview.