Participatory Community Involvement in the Planning Processes of Building Projects – A Social Psychological Approach 1 Maria Luisa Lima 2 , Sergio Moreira 3 & Sibila Marques 4 Maria Luisa Lima She is a full professor in environmental social psychology at ISCTE-University Institute of Lisbon. Her research interests on risk perception and communication have lead to the involvement in numerous national and inter- national projects and publications. Besides, since 1997 she has provided consultancy expertise to a range of private and public sector organizations on the issues of risk communication and involvement of communities in decision making processes. Sergio Moreira He is a PhD Social Psychologist from ISCTE-IUL and an Environmental Psychology consultant at ESPA. Over the last years he has produced fundamental research in Social Cognition, particularly in the study of memory illu- sions and stereotypes malleability. More recently he has coordinated and executed projects on real world prob- lems involving the assessment of communities perceptions regarding complex environmental changes and the promotion on communication and public participation. Sibila Marques She is an invited assistant professor at ISCTE-University Institute of Lisbon and a pos-doc researcher at Centre for Psychological Research and Social Intervention (CIS-IUL). Since 2002, she has worked as a consultant in en- vironmental psychology and has collaborated in several projects related, for instance, with the identification of psychosocial impacts of hazardous facilities and in the promotion of local involvement with communities. She has also relevant publication in this field and has presented her work in several international contexts. Umweltpsychologie, 16. Jg., Heft 1, 2012, 68-87 68 Schwerpunktthema Abstract This paper describes a consultancy project aimed at designing and implementing a public participatory process for the planning of two dams in Portugal. This intervention was inspired by a social psychological ap- proach developed by Abrams, Hogg and Marques (2005). The project’s three specific aims were: (1) to change perceptions held by the dam developers: i.e., changing the orga- nizational culture, the dominant attitudes and representations company members had towards the local communities, making