The internal courtyard of mixed use buildings, a device of thermal and luminous comfort

International audienceThe historical patio-courtyard is an outdoor area largely or entirely surrounded by buildings or walls. Generally, the courtyards are useful to sunlighting because their open spaces preserve the solar access of the adjoining buildings. They allow sunlight to reach the facades so that side-lighting strategies can be used. In urban fabric of the Mediterranean countries, we observe a new generation of big patios with mixed-use buildings (housing, trade, offices). This may be a return to the traditional form of the patio, which allows a passive regulation of built environment, multi-use activities, and security of the inhabitants. This new interpretation of a traditional passive device suggests more problems of illumination on lower levels. It becomes necessary to assess the performances of different courtyard shapes that behave as shafts. This paper presents the influence of the courtyard shape and orientation, on sunlighting duration and illumination levels of ground and facades. The results enable to propose changes of the distribution of the uses through the facades, vertically or horizontally, according to the orientation preferred and the illumination for each use