The remodelling study of heating and cooling installations of the municipal sports centre of Ordizia (Spain) has been widened including a renewable energy proposal, integrating also the concept of life cycle analysis (LCA) of the installation which allows therefore, to analyze the environmental impact prior its approval and implementation. The analysis of the inclusion of two set of solar panels (thermal and photovoltaic) in addition to the substitution of the old diesel boiler by a more efficient natural gas equipment, in order to satisfy the power demand of the installations, has been studied by means of life cycle analysis. The supply directly from the grid is the alternative with the greatest impact, while the photovoltaic is the most efficient one from an environmental standpoint. However, when solar irradiation is insufficient for the needs of the sports centre, a hybrid system is the best choice. In a similar way, in order to satisfy the heat demand, the combination of thermal panels with the natural gas boiler has been proven to be a good solution.