Delay and/or load estimation is performed prior to physical layout in an integrated circuit (IC) design process. Initially, a description of the IC design is obtained, the description being in a hardware description language (HDL). Floor planning is then performed based on the HDL description, and buffers are inserted into the IC design based on such floor planning. Finally, delays and/or loads are estimated in the IC design while taking into account the effect of the buffers. The buffers are inserted in the foregoing processing based on anticipated processing later in the IC design process.