In the buildings sector, the use of ventilated double skin facades in order to reduce the energy demand and the environmental impact of the building during its operational phase has grown significantly. However, the use of this constructive system could lead to high environmental costs during the manufacturing and dismantling phase of the building. This paper presents a life cycle assessment (LCA) study based on the EcoIndicator 99 of a ventilated facade with PCM in its air chamber. Two cubicles were built in an experimental set-up located in Puigverd de Lleida (Spain), one with this ventilated facade system and the other without. The differences in the electrical energy consumption of the HVAC systems were registered and used to determine the environmental savings produced during the operational phase of each building. The results of the LCA show that considering a lifetime of 50 years, the use of this particular ventilated facade reduces by 7.7% the overall environmental impact of the whole building. It also highlights that the environmental payback of this active system is significantly lower than other systems which use PCM in the building envelopes. The environmental payback of the system is 30 years, which can be reduced to only 6 years if instead steel wood would have been used in the structure.