One of the preconditions for genuine sustainability is a heritage that is present anywhere and anytime in everyday life. We present PLUGGY, a Pluggable Social Platform for Heritage Awareness and Participation. PLUGGY will address the need of society to be actively involved in cultural heritage activities, not only as an observer but also as a creator and a major influencing factor. With PLUGGY, we aim to bridge this gap by providing the tools needed to allow users to share their local knowledge and everyday experience with others, together with the contribution of cultural institutions. Users will be able to build extensive networks around a common area of interest, connecting the past, the present and the future. It will be powered by its users and puts people's values, aspirations and needs first. Users of PLUGGY will be the providers of information about cultural heritage in the everyday and ordinary, real life. Through its social platform and by using its innovative curation tools, designed to solely focus on a niche area in social media, citizens will be able to act as skilled storytellers by creating fascinating personalised stories and share them through social networking with friends, associates and professionals. In this paper, we describe a structured formative and summative evaluative approach of PLUGGY's core concepts, which results will be used to inform and improve its design.