Abstract: The invention relates to a system and method for monitoring and managing the energy efficiency of buildings, comprising data-acquisition devices, a communication network, a server that stores and processes the information, and a procedure for optimising energy consumption forecasts and economic evaluation of improvement alternatives. The monitoring and management method comprises the following steps: measuring; transmitting, receiving and transferring data; and processing, storing and interfacing with the user, wherein the interface with the user comprises three main modules, namely the alarm module, the monitoring module and the investment options module. In particular, the investment options module is for generating investment recommendations on the basis of improvement alternatives in terms of energy and/or services efficiency, with economic evaluations of the impact and profitability of the implementation of any of the proposed improvement alternatives.