The main problems in multi-storey building envelopes in Portugal are the low thermal insulation and low airborne sound insulation. These problems are more relevant in buildings built before the publication of the first thermal code. The envelopes, mainly the façades of buildings built in that period, do not fulfill the actual users comfort requirements and construction codes. This way, it is necessary to find the most appropriate technical solutions to refurbish those façades. One of most used technical solutions is the ventilated façade. In this paper the impacts of this technical solution in standard envelopes are going to be discussed. The impacts will be assessed looking at technical, functional, social, economical and environmental proprieties.