Heritage is a way of affirmation of the territory, by carrying its strong identity character, and is an existing resource that is necessary to protect and preserve. In the post 25th of April 1974, in Portugal, in the residual and peripheral areas, collective dwellings of cooperative housing were built, some awarded for their quality. These buildings are recent heritage and future legacy. Though they are an informed architecture, are immersed in an identity geographical context, which gives them a soul of their own. Due to the present austerity, the crises and to the gap left by the Exceptional Regulation for Urban Rehabilitation many of these buildings will not be preserved, thus facing a rapid degradation. Due to the impossibility to preserve everything is necessary to define authenticity criteria in their conservation and rehabilitation, based on buildings referenced by INH/IHRU, which can be used to access other buildings referenced or not.