The aim of this project is to improve the planning support system LEAM for use in Stockholm, as well as to use it as a tool in investigating which factors drive development in the Stockholm region, and how this can be used to guide future development to be as sustainable as possible. The details of the data assembly and modifications made for the improvement of LEAM Stockholm are included in this report, together with suggestions for further improvements. Four different scenarios for development in Stockholm were tested during this project, and the results of these scenarios are included here. Based on these scenarios, transportation (road) networks and growth limitations imposed by the planning authorities (no-growth zones and municipal density targets) were found to be those drivers which have the biggest effect on directing the urban growth. These drivers could also be used effectively in guiding urban development for improved watershed management and reduced urban greenhouse gas emissions.