The present work is aimed at evaluating the influence of various factors - mainly number of users - on both energy and environmental features of a Health Centre by quantifying their incidence on the sizing of the building, as well as on energy consumption and its management. A total of 70 Health Centres located in eight Health Areas of Extremadura (a south western Region of Spain) were analyzed from both energy and environmental perspectives. In particular, the most influential parameters on buildings' daily management were studied. Also, a sensitivity analysis to establish empirical connections between energy indicators and the operating parameters was carried out. Finally, Geographic Information Systems (GIS) were used to explore possible correlations with other factors related to buildings' location. (C) 2011 Elsevier B.V. All rights reserved.