If we now compare the behaviour of new and old buildings (B7 and B14) and, at the same time the effect of plaster and marble external coating (B11 and B14), we obtain Figures 11 and 12. From these figures, we can conclude that it is not the effect of the ex-ternal coating which shows the higher influence over a building's
indoor ambience, but that it is the type of brick that is mainly
responsible for this.
From Fig. 10, we can see the similitude between new and old buildings with plaster coating during the dry and rainy seasons. From
this figure we can observe that during the working hours (07:00–17:00), there is a clear difference between new and old
buildings' behaviour. Despite this, it is only statistically representative during the few initial working hours of the dry season, as can be seen in Fig. 6, with values below 0.05. Furthermore, at the exact time when the office closes (17:00), and during the four closing hour periods, there is a clear difference in indoor ambience behaviour with a significance value below 0.05 in rainy
and, in particular, dry season. At 22:00, the hygroscopic effect of the building wall construction materials perform their activity, and the indoor ambience tends to stay at the same level up to 6:00.
During this unoccupied period, despite the fact that the significance level is clearly over 0.05 and, consequently, indoor ambiences can be considered to reach the same behaviour, we can see that there is a clear, greater tendency to reach a similar behaviour between new and old buildings during the rainy season than in the
dry season.