Plus Energy house with natural materials (Section). The building is heated with sun energy heat gains, internal human body energy gains and heat exchanger system, which fulfills also the ventilation. The sun angles are researched both in winter and summer. The living rooms are oriented on the south, but still there are windows on the north, which give the inhabitants nice mountain views on the north, both natural light and ventilation. Complete building envelope without thermal bridges from straw bales and light clay with high levels of airthightness through the clay plasters – both interior and exterior. The clay provide natural optimal control over temperature and humidity, sound- and electromagnetic protection. During the winter, the thermal mass of the clay walls, floor and roof provides additional heating. The wood constructions steps on concrete foundations and the building is raised over the ground, which enable s natural ventilation of the construction. Heat exchanger system with more than 93% heat exchange provides partly the heating and the ventilation. Chimney effect can be used for summer natural ventilation. Solar panels with a solar boiler cares for the heating (floor and wall hot water system). Building integrated Photovoltaics supply the house with energy. The additional energy for electricity needs and heating are supplied by centralized systems. The rainwater is stored in a rainwater collector under the building and passes throgh a system of breakstones. Part of the rainwater is absorbed by the green roof and the northern green walls.