## 3 Results and Discussion
According to residents who have renovated their properties, the walls are composed of ceramic blocks, and the slab is composed of concrete, approximately 10 cm in thickness. The roofing of the building is composed of fiber cement without special paint or a thermal blanket. The outer walls are painted with colors visually similar to dark green, with an absorbance of 0.7, and ivory (color 12), with an absorbance of 0.34. The walls comply with the RTQ-R transmittance and thermal absorbance requirements; however, the roofing does not (Table 4). The apartments have individualized energy measurements, but the building has only a single, combined measurement for drinking water consumption. Only the toilets with attached boxes can be considered water conservation equipment in the HUs. When analyzing the degree-hours indicator for cooling (cooling for summer) for the three floors using Table 5, the thermal performance of the envelope of the naturally ventilated building is better in the apartments on stilts and facing south and worse in the apartments on the top floor and in the smaller bedrooms with two external walls, one of which faces north; these bedrooms receive solar incidence for most of the day. The shading due to the shape of the building also favors a good performance of the interior spaces. Thus, of the 24 apartments, 21 received classification C for the envelope performance for summer, two received classification B, and one received classification D. Regarding the relative refrigeration (artificial cooling) consumption, the smaller bedrooms, particularly those on the intermediate floor, have the worst performance. The best performance is in the two larger,  
Figure 5: Percentage of natural light in the extended-use spaces (EUSs) of the representative buildings. Figure 6: Percentage of natural ventilation in the EUSs of the representative buildings. south-facing bedrooms with few exterior walls and on the top floor. The type of water heating system in the building influenced the final classification of the HU, resulting in 20 HUs with a classification of C and four with a classification of D. Thus, the classification of the multi-family building as a whole is C.  
Building B represents the 135 buildings classified in typology 2, i.e., 20% of the 663 buildings surveyed. Similar to the representative Building A, Building B was approved in 1981 and has four floors: A ground floor on stilts and three floors with standard apartments (similar floor plans), with eight apartments per floor: Four facing east and four facing west (Table 6). Living room balconies and the shape of the building serve as shading elements. The largest bedroom does not meet the minimum lighting percentage (12.5%), but the other two do. None of the bedrooms meet the minimum ventilation percentage for BZ 8 (10%), but the living room meets both lighting and ventilation requirements. Cross ventilation is present in all the apartments, and one out of the two bathrooms has natural lighting and ventilation. Buildings B has the same specifications for the process of constructing the envelope and roof, as well as the same external color as Building A; consequently, it has the same values for thermal transmittance and absorbance. The apartments have individualized energy measurements, but the building has only a single, combined measurement for the drinking water consumption. Only the toilets with attached boxes but without a dual flush can be considered as water conservation equipment. As shown in Table 6, the thermal performance of the envelope of the naturally ventilated building is better in the apartments on stilts and facing east. The balconies and building shape helped to raise the ranking of some EUSs, both for cooling for summer and for artificial cooling. The worst performance occurred in the apartments on the top floor and in the smaller bedrooms with two external walls, especially when the walls are facing west and north.