Gives the results of an investigation on the combined effect of balcony, opening design and internal division on the indoor airflows pattern of a living zone located on the second floor of a two storey building. It was done using N3S software. The local average velocity coefficient as a function of the position in horizontal sections of 1.00 and 1.50 m in height was used, for activity with sitting and standing positions. The number of measurement points in the living zone were used to calculate the average velocity coefficient. Concludes that opening and balcony designs are helpful for increasing natural indoor air movement but not for the modification of internal divisions.