In covered mall buildings, a plastic sign must be a maximum of ___ % of the wall area facing the mall.

In covered mall buildings, regulations concerning signage are in place to maintain a harmonious and visually appealing environment. The correct figure for the maximum percentage of wall area that a plastic sign can occupy is 20%. This guideline helps ensure that the signage does not overwhelm the aesthetic of the mall and allows for a balanced view for shoppers.

Specifically, limiting the sign area to 20% of the wall facing the mall prevents excessive visual clutter, which can detract from the overall shopping experience. It also ensures that businesses can advertise effectively while contributing to the overall design integrity of the mall space. Using this percentage promotes both the visibility of individual stores and a cohesive look throughout the shopping area.

Other percentages provided in the choices either exceed reasonable limits for maintaining visual quality or fall short of providing sufficient exposure for signage needs, thus illustrating the importance of striking a balance in mall design regulations.