The goal of this project is to apply data analytics methods to improve energy efficiency in buildings based on automatic description of monitoring data, prediction of future energy needs and prescribing measures to reduce energy usage. By continuously collecting realtime monitoring data, the algorithms can automatically improve prediction accuracy and prescribe better decision options. Methods such as data mining of monitoring data, forecasting and simulations are used to create recommendations for optimization of building energy efficiency. By optimizing the energy consumption to the needs of occupants and energy availability from renewable sources the solution can maximize the comfort and reduce the costs for energy.