The energy consumption of a building is evaluated by neglecting the heat loss which can occur when the air passes through the envelope. However, recent studies showed that air leakage plays asignificant role by affecting the thermal performances of walls and the energy consumption. Moststudies have focused on the quantification of air leakage flows through the building shell, withoutaddressing the problem of the heat exchange between this airflow and the construction materials asthe air passes through the envelope.