This research will analyze the formation and evolution of regional policy networks involving both public and private stakeholders in the emerging sector of Green Building Technologies1 (GBT). Networks will be considered as a form of governance system and emphasis will be put in the formation and management of these networks as well as the way in which they decide about the selection and application of activities and policy instruments. The study investigate local stakeholder interactions as well as articulation and interdependencies with other actors in a multilevel environmental governance system2. The general background of this study will be the process of implementation of policies on GBT which emanate from higher policy levels such as EU, and central and regional Spanish governments.