Area padding is the amount of overhead space allocated to area groups when determining the default minimum size of the area. You cannot create an area group that is smaller than the number of slices required to contain all the logic in the hierarchical block that is assigned to the area group. The minimum size always includes a "padding” value over the absolute logic symbol count to allow for typical slice utilization efficiencies. The default value is 25%.
Use the Area Padding command to turn area padding on or off. When turned on, the Area Padding dialog box appears. Use this dialog box to specify the padding used when creating and resizing areas in your design. The range is from 0 to 200 percent.
Menu item: In the Areas menu, click Area Padding.