In the wild, cover is used by animals to seek shelter from the elements, protection from predators and aggressive conspecifics and as a way to reduce inter-animal communication. Rearing environments for captive raised fowl often contain open areas that are lacking in complexity and that are greatly underused. As a result, use of space within pen-type enclosures is often not uniform. This paper investigates the effect of increased environmental complexity on the use of space by broilers. The experiment consisted of three cover treatments (mesh panel, frame panels and no cover) and three group sizes (80, 110 and 140). The vertical panels, constructed of PVC piping, were positioned in pen centers, while the pen centers in the no cover treatment were left empty. It was hypothesized that the provision of vertical panels to pen centers would attract birds into the central space and would lead to a more uniform distribution of birds. Using a grid-coordinate system set up in each pen, scan samples were taken on the use of space in each pen four times per day, 3 days per week from 5 to 44 days of age. Use of space in the central region for the two cover treatments was significantly higher than for the no cover treatment (P < 0.0001). The effect of cover treatment on the mean percentage of birds using the central space was influenced by age (P < 0.0001) and by group size (P < 0.05). Differences in the use of space between the frame and mesh treatment were only found during week 1. In the side, end and middle regions surrounding the panels, use of space was influenced by cover treatment and age (P < 0.0001). Over 80% of the use of pen center occurred at the ends and sides of the panels. These results support the hypothesis that the presence of vertical panels results in a more uniform distribution of birds within the pen by increasing the number of birds using the center.