A new approach to performance-driven placement based on a window concept is presented. Timing constraints are first converted to geometric shapes using the defined windows. A window represents a region in which all the modules along a given path can be placed without degrading the circuit performance. Then a constructive placement process uses the window information to select an unplaced module, and to find an appropriate position for the module. This approach represents a unified way to consider both timing and geometric constraints during the VLSI placement process. The experimental results show that improvement of circuit performance can be achieved by sufficient use of the window information.