ABSTRACT. Semi-outdoor spaces with transient usage demand a particular refinement in the level of detail required for the estimation of comfort. The present work first exposes a method to reduce uncertainties in building natural ventilation using urban wind simulation. The hourly indoor air velocities are also estimated with this method and feed the yearly comfort calculation. The transient comfort index Out_SET* including modifications related to the effect of wind on clothing thermal and evaporative insulation is used as a reference for thermal perception. An opening treating of the influence of the metabolism's history on comfort perception is proposed as a conclusion.