“Powerhouse” is an alliance that will demonstrate that it is possible to build plus-energy buildings in cold climates, such as in Norway. For the Powerhouse project in Trondheim (Brattørkaia 17a), PV panels will produce and offset the delivered energy needed during the operation and for compensating the embodied energy of the building. The building will thus export more electricity than it will use for operation. In a broader environmental perspective, an aim of this project is also to achieve the classification “Outstanding” in the BREEAM-NOR environmental certification scheme. Energy efficiency measures and materials with low embodied energy have been crucial for obtaining the energy goal. A very efficient ventilation and passive cooling concept is being developed. The architecture does highly reflect the plus-energy goal, both regarding the form and the energy production surfaces (roof and the facades). The Powerhouse project is a ZEB pilot building, i.e. a pilot within the Research Centre on Zero Emission Buildings. Therefore an aim is also very low greenhouse gas emissions during the building’s lifetime. Calculations indicate that the energy balance during the building’s lifetime, and within the defined definition, is close to the goal. However, there are still relative large uncertainties related to some of the figures, in particular the embodied energy for the materials.