In this paper a numerical software, that simulates the building thermal behaviour with complex topology in transient conditions, was developed and used in the study of kindergarten thermal response and the occupants’ thermal comfort and air quality in Mediterranean conditions. In this numerical model a new building three-dimensional grid generation philosophy, closer to the reality, that considers the building and the surrounding buildings used in the long and short-wave calculus, the external and internal shading devices, the energy and mass balance integral equations philosophy generated by the building geometry, the equation system resolution done by the Runge-Kutta-Felberg with error control and the human thermal comfort level evaluated through human thermo-physiology, are developed.

In the simulation, with a real occupation cycle, the compartments, the building opaque bodies, the building transparent bodies, and the external shading devices were considered. In passive strategies the kindergarten is equipped with multiple inclined aluminium shading devices placed above the transparent windows level and in front to the transparent door facing south, removable inclined tissue shading devices placed in front to the transparent windows facing east, and horizontal fabrics shading devices placed above the transparent panel levels facing south, south-west and west.

In this study, made with natural and forced ventilation, the summer and winter conditions were used. In summer conditions, the forced ventilation active strategies in all spaces with cold air from the external environment during the night, and in occupied spaces with stored cold air from the underground space were used. In winter conditions forced ventilation from an internal greenhouse, to heat the internal occupied cold spaces, was used.