Existing tool for environmental impact assessment of buildings and districts according to the LCA procedure are based upon a static method, considering yearly average processes and impacts. A dynamic method has been developed in order to model the temporal variation of electricity production and allocate environmental impacts to different uses. It allows to evaluate low-energy and plus energy buildings on a more precise basis. Based upon data from the French electricity grid manager, the model evaluates the production mix in terms of temperatures in French climates and several periodic functions corresponding to variation frequencies identified by a Fourier analysis. In a second step, specific production mixes are derived for different uses: heating, cooling, domestic hot water, domestic appliances and office appliances. The model has been tested on a single family passive house, allowing solar hot water and photovoltaic systems to be assessed using a dynamic method.