Urban planning in Europe is currently undergoing a darastic change both in style and substance, mainly due to the initiatives and financial assistance of the Euripean Union. The basic philosophy underlying the rennaisance in urban planning in Europe is based upon the four basic principles advanced by Jane Jacobs in her classic Death and Life of Great American Cities, 1961. In this article, Jane Jacobs's four basic principles are briefly examined and the case of Rouvain la Neuve is described to illustate the implications of Jane Jacobs's philosophy.