Aspects of the invention include a computer-implemented method of hierarchical large block synthesis (HLBS). At least a partial ring is created around an HLBS structure. The partial ring includes at least one or more of filler elements, which are engineering change order (ECO) books for adding repeaters to wire dominated nets, and decoupling capacitors of relatively large sizes. Certain areas of the HLBS structure within the partial ring that exhibit a unique characteristic are identified. Decoupling capacitors of the relatively large sizes are disposed in the certain areas. A remainder of the areas of the HLBS structure are filled with engineering change order (ECO) books and decoupling capacitors of relatively small sizes.