Abstract

STRACT One of the characteristics of passive low energy architecture is the dependence of its facades on solar access. However this aspect is little considered by law or in the practice of real estate development. On the one hand, urban space configurations such as streets are defined in planning guidance by law to safeguard the common good, but on the other, real estate activity puts pressures on land and creates large buildings occupying maximum plot ratio. This is particularly the case in developing societies and emerging economies. One of the direct effects of this process is solar obstructions on the urban space, i.e. facades, ground and sky. This means that indirect passive low energy opportunities which affect the possibility to capture energy for passive or active systems are lost with new high-rise developments creating unequitable environments. Therefore, the design of urban space which considers solar access to facades becomes an important issue as a means to avoid these problems. This paper seeks to explore designs which permit solar access within the context of urban practice which permits large building volumes. Here different street configurations are examined to evaluate to what extend it is possible to balance solar access and plot ratio criteria in planning guidelines. This investigation examines four urban space configurations from lower to higher density to discover the range in which both criteria present compatibility. Two cities located at two different latitudes are compared to assess solar irradiation availability on the surfaces of facades, the ground, the roof and the urban space. A simulation was carried out on winter and summer solstice with 2 urban orientations: east-west and north-south axis. Results show an inflexion point in the curve of irradiance according to geometrical profile. These findings help to orientate planning guidelines in the consideration of passive low energy architecture to promote a more sustainable habitat in developing societies.