Affordances are design clues that allow users to effortlessly determine how objects should be used. Since their introduction to the human–computer interaction design community, their use within interfaces has become a staple. But, despite work to understand how affordances make an interface's available actions transparent, few empirical studies have examined the cognitive origins of this interaction type. Therefore, we explored the impact of cognitive load on affordance‐based interactions. Participants were asked to perform a series of affordance‐based interactions while under different types of working memory load (no load, verbal, spatial, and central executive). Affordance‐based interactions were consistently slowed under central executive load, but never when under verbal load. We conclude that affordance‐based interactions do require cognitive resources, but resource costs may only manifest under heavy load. With this knowledge, designers may be able to better predict when an affordance will (or will not) act as if it is resource free. Copyright © 2016 John Wiley & Sons, Ltd.