The building sector consumes 32% of global energy used, and it is responsible for 20% of total greenhouse gases emissions. In Europe, more than one third of the buildings are 50 years or older, thus, it is critical that new dwellings are designed in the most efficient way from an energy perspective, since the consequences of the decisions taken today will remain during decades. The use of Building Information Modeling (BIM) software is promising for the design of a wide range of constructions; from small dwellings to big apartment buildings. These programs allow the architect, designer or civil consultant to perform several simulations of the energy behavior of a building in a timely manner, even before a single brick is put in place. Among them, IDA ICE software utilized in this thesis is a top rated program, situated by some authors within the four main building energy simulation tools. This is an outstanding fact considering that it is estimated in more than 400 the number of available BIM programs. With the help of IDA ICE it will be demonstrated that for a dwelling object of study, located in Madrid (Spain), it is possible to save up to 4 250€ through the entire life of the building if the proper orientation is chosen. The discussed literature and results will also show that orientation is, by far, the most critical passive design parameter related to a building, from which the efficacy of other related measures depends on.   It will be also proven that the optimal orientation depends on the weather where the dwelling is located, even though a general trend consisting in orienting the houses located in the northern hemisphere to the south, and vice versa, is observed. Building orientation, BIM programs, building energy consumption, passive design parameters, IDA-ICE simulation tool.