Educational buildings have been object of several activities by ENEA (Italian National Agency for New Technology, Energy and Environment), referring to the possibilities of energy saving in accordance with the comfort and the hygiene regulations provided by the law (see Acta of the seminar: `Interventi di miglioramento energetico nelle scuole`, Roma, 26-27 ottobre 1989). The present work is the first concrete experience of collaboration with a municipal enterprise (AMCPS) which manages the school buildings of the Municipality of Vicenza. In particular, we have analyzed the interventions on the building envelope (substitution of windows and doors, insulations by modern technics, elimination of old dampers for ventilation, installation of heat regenerator from exhausted air, improvements on lighting sources, etc. ) and on the heating plant and hot water production (substitution of old boilers with high efficiency boilers, reduction of thermal losses from piping, etc. ). These actions have been defined on the basis of an extensive acquisition data about the comfort within some schools whose heating plant is managed by AMCPS.