An increasing interest and application of the glass material in architecture and Portuguese construction can be observed through the buildings of the built where it is more used in the service buildings-Fig.1.

It is a common sight in the service buildings (mainly office buildings) built in the last decades, the glass material as constituent part of the envelope and in considerable proportions. The residential buildings, usually present, lower glazing areas than the service buildings. Meanwhile, it is possible to note a growing increase in the glazing areas in the facades of the residential buildings built in the last decades (Fig. 2), and even, some of the residential buildings built in the last years have practically glassed facades similar to the service buildings, see Fig. 3.

1970

Fig. 2. Evolution of residential buildings and glazing areas in the last decades (Valmor Awards).

Large glazing areas in residential buildings are architectural solutions or options that allow a more homogeneous exterior aesthetic view, scenery contemplation, greater transparency and luminosity; while having a direct influence in the comfort of its occupants, and are determinant for the building thermal-energetic performance (large glazing areas in a residential unit increases the potential for heat gain or loss). The residential buildings highlighted in Fig. 3 were selected for this study. Some flats of these buildings were monitored through the summer (2007) and winter (2007-2008). In this way this work will show the main results and observations of the monitoring.