Improving ventilation and envelope characteristics in order to decrease the energy consumption in existing buildings

The building sector represents a great percentage of the total consumption of energy of a country, and of this, most is due to the existing buildings. The great number of existing buildings in comparison with the new buildings, and the worst constructive quality in the first ones, they explain the previous asseveration. It is, therefore, of a primordial importance, to promote measures guided to limit the energy consumption in these buildings, what can be obtained through the rehabilitation of the same ones. The aim of the paper is to study the improvement of applying global strategies that promote the efficient energy consumption of refurbished buildings. The first task to solve is the evaluation of the different contributions to the overall energy consumption in a building. Thus, from this study, it can be deduced what kind of rehabilitation proposals have a greater potential of energy saving. The rehabilitation proposals will consider the use of passive and active systems; these techniques will deal with advanced glazing systems, natural ventilation, active solar systems and PVs, passive cooling techniques, advanced and integrated solar control devices and best integration of the components to the building envelope. These strategies and techniques have already reached a certain level of architectural and industrial acceptance however they have been used independently and for new buildings. The novel in this paper consists of the study of the different measures individually and then joint in order to obtain the best solution in the rehabilitation of existing buildings.