[eng] In this article, the authors estimated the saving potentials in the embodied energy and CO2 emissions, which could be achieved through a replacement of the most energyintensive elements in a large building. The results showed that 75% of the embodied energy came from only a small group of the building components, that reductions from 14% to 29% in embodied energy values were possible with simple replacements and that between 1770 and 4160 tonnes of CO2 could be avoided to be emitted to the atmosphere, with budget increases lower than 8%.