A method, computer program product, and data processing system for porosity-aware buffered Steiner tree construction are disclosed. A preferred embodiment begins with a timing-driven Steiner tree generated without regard for porosity, then applies a plate-based adjustment guided by length-based buffer insertion. After performing localized blockage avoidance, the resulting tree is then passed to a buffer placement algorithm, such as van Ginneken's algorithm, to obtain a porosity-aware buffered Steiner tree.