In Berlin, the German Federal Ministry of Transport, Building and Urban Development (BMVBS) had a model building erected to pilot the new funding initiative 'Efficiency House Plus'. This model is also intended to test and prove the performance of various components of the concept and to provide experience for a wider application. During a 2-year monitoring programme conducted by Fraunhofer IBP, data of the occupied building will be measured and analysed with regard to its energy performance. This report presents the first preliminary results obtained from a 12-month survey period. Measurements found that - despite unfavourable meteorological boundary conditions - the power yields from façade-integrated PV systems still exceeded the energy needs of building services and building users during the survey period. The resultant surplus energy was used to cover about 25 % of the energy demand for electro-mobility. Under 'regular' weather conditions the House would have been able to completely cover the energy demand of the electric vehicles, and still there would have been energy left to be fed into the public grid. The meteorological boundary conditions that were prevailing in the measurement period from March 2012 through February 2013 caused a 20 % drop (3,320 kWh) in the solar power yield due to an actual reduction of the sunshine hours, which were about 40 % less than the annual average of the last ten years. In the survey period, the energy consumption in the building was about 75 % higher than predicted. This discrepancy was mainly due to the inefficient performance of the heating system (caused by substantially higher system temperatures than assumed). It was further due to the uncontrolled amount of outdoor air in the mechanical ventilation system and last but not least it was also due to the fact that the electricity consumption of household appliances was higher than expected. The results of the first year of operation suggest that in the case of high-performance buildings it is absolutely required to include a planned monitoring and regulation/control phase, to be capable of realising the design parameters in practice