A method for placing spare cells into an auto-place-route (APR) block of an integrated circuit is disclosed. The list of functional cells to be included in the block is determined along with the netlist. The sum of the areas of the functional cells and the desired spare cell area is used as the area of the block boundary. The boundary is provided as input to an auto-placement tool along with the netlist and the list of functional cells. The list of functional cells specifically does not include the spare cells so that the tool does not place spare cells in the boundary. Consequently, the spare cell area may be utilized as wiggle-room by the tool to efficiently place the functional cells. The tool produces a placement of the functional cells that includes white space in the boundary. Spare cells are then placed into the white space.