NET-ZERO ENERGY BUILDINGS

Actually we can describe them as the buildings that need during a year so much energy as they are able to produce (through the active solar systems or technologies that use the mini:mum of fossil fuels). The main subject of this text is the area of internal gains with respect to their utility for heating system. The volume of internal gains is connected with using technologies and facilities in the building so it depends on the operation in the building and on the behaviour of its users. The analysis focused on the specific energy need for heating shows the dependence on the volume of internal gains. For design of NZEB are important the accuracy of input information about the internal gains. We can extract them from exact operation data or from exactly defined operation characteristics that we get from the validation of measuring data (from experimental measurement) and from the analytical model of building operation. The main goal of designing NZEB should be the minimization of all input conditions (built-in energy from the construction, energy for operation of the building, production of emissions CO(2) and SO(2), finances for construction and operation of the building, other environmental influence water requirements, waste production,...) and at the same time to hold the standard of living with respect to social and cultural aspects.