The environmental response of office buildings from the Brazilian bioclimatic modernism in São Paulo: the case study of Complexo Conjunto Nacional – CCN (1962)

Abstract

In commercial buildings from the Brazilian modernism (1930 -1964), narrow plans allowed for good daylight and natural ventilation. However, little is known about the environmental performance of those buildings. Economic pressures led to a proliferation of tall office buildings of larger floors and sealed facade, with major impacts on buildingś thermal behaviour. In this context, the objective of this technical study is to draw lessons from the performance of the iconic office building of Complexo Conjunto Nacional (1963), in São Paulo (24oS), with focus on its thermal response. Since the case-study building has no external shading, the counter effect of thermal mass from the concrete structure, coupled with the potential of natural ventilation, was examined by means of fieldwork and analytical studies. The relation between orientation, solar exposure and daylight was also addressed by measurements as well as the impact of operable windows in the internal acoustic environment. Thermodynamic simulations revealed that comfort can be achieved for more than 85% of occupied hours in the hottest month of the year, with passive means. Daylight measurements showed that illuminance levels remain within the visual comfort range, when direct solar radiation is not impinging on windows. Noise levels above the recommended by national standards were registered with windows opened and closed. Nevertheless, regardless the acoustic conditions, fieldwork confirmed that some occupants choose to open windows for natural ventilation at various heights in both buildingś orientations. The work presented here is part of the research project quoted in Gonçalves et al. (2018).